Full text of "Radio Electronics (42 issues)"

See other formats

COMPUTERS - VIDEO - STEREO - TECHNOLOGY - SERVICE

:VELANO

UNLEADED FUEL CWDC

PLUS:

★ Videogames ★ Hobby Corner

★ Drawing Board * Service Clinic

★ New Idea ★ State- Of- Solid-State

precision

Excellence by Design

BBC has been building multimeters and
other instrumentation for European
engineers and technicians for over 7
decades. And now, twelve advanced
technology BBC meters with a complete
line of accessories are available in the
U.S. Prices range from under $50.00 to
$595.00. No other manufacturer offers
you comparable price and performance
values.

Forms that Follow Function

To achieve a family of “hands free”
instrumentation designed for heavy-duty
use in a wide variety of environments,

BBC relied on the industrial design skills
of the Porsche Design Studios. You’ll like
the results.

The unique folding design lets you adjust
the viewing angle. Extra large LCD
displays make the meters easy to read.
The exclusive function and range switch is
logically laid out. And the folding meters
even turn off automatically when you
close the case.

Accuracy Where it Counts

Precision is a tradition at BBC. The 3V2
digit folding models feature 0.1 % basic dc
accuracy. For higher precision
measurements, the model MA 5D delivers
0.05% basic dc accuracy and 30,000
counts.

Precision Values

Some of the best news about BBC meters
is that you can get them for less than
you’ve been paying for old technology
meters. They are built to the world’s
highest safety standards, VDE/DIN, and
are backed by one of the strongest
warrantees in the industry.

Local Availability

BBC has worked hard to make these
meters available through leading U.S.
distributors and representatives. There is
an outlet close to you. And, if your
instrumentation supplier doesn’t carry
BBC yet, we’ll gladly tell you who does.
Call toll free: 1 - 800 - 821 - 6327 .

(In CO, 303-469-5231)

□ Send me
information on
BBC meters.

□ I’d like to
be on your
mail list.

BBC-METRAWATT/GOERZ

6901 W. 117th Avenue
Broomfield, CO 80020
Telex 45-4540
(303) 469-5231

Fast-Response Coupon

Name

Title

Company
Address _

City State Zip

Telephone ( )

Engineering Excellence in Test and Measurement

BBC

GOERZ

METRAWATT

CIRCLE 60 ON FREE INFORMATION CARD

SENCORE MODEL SC61

WAVEFORM ANALYZER

Double Your Troubleshooting and Testing

Productivity ... Or Your Money Back!

Six-digit readout: Auto-
matically tracks every
CRT test. We call it

digital autot racking

It’s patent pending.

DIGIT A I.
READOU1

VOLTS/DIVISION

CHANNEL A

VERTICAL

POSITION

INPUT COUPLING

FREQ

One probe input: One

probe input per
channel for all
measurements -
^digital and scope -
Wh 5 mV to 2000 V
measuring range. (2
lo-cap probes
provided.)

VOLTS/DIVISION

CHANNEL B

VERTICAL

POSITION

INPUT COUPLING

Delta PPV, Time, Freq:

Measure any part of a

FREQ

waveform for PPV,
time or frequency
using Delta measure-

A DELTA MEASUREMENTS

TRIGGER

SOURCE

MODE

A INTENSIFIED &
BEGIN PORTION END

merits. Just dial in the

waveform section
you want to measure

TIMEBASE-FREQ

Super sync: ECL

provides rock-solid
sync trigger circuits

POLARITY

HORIZ

POSITION

INTENSC

FOCUS

4 controls;

Simplify Freq ratio tests:

Automatically
compare input/output

includes TV sync
separators for video
work.

GROUND

SEAM

FINDER

ratio of multiply/divide

iWKJCFSSOft l
. USEAKUg TO

MODEL SC61

WAVEFORM ANALYZER

push of a button.

U.S. Patent Pending
Financing Available

The first scope with push button
digital readout. If you use general
purpose oscilloscopes for trouble-
shooting or testing, we can double
your present productivity with the
SC61 Waveform Analyzer, the first
instrument to turn every conventional
scope measurement into an
automatic digital readout.

No more graticule counting.
Connect only one probe to view
any waveform to 1 00 MHz. Then, just
push a button to read DCV, PPV,
frequency and time — automatically!

There are no graticules to count or
calculations to make, which speeds
every measurement.

The digital readout is from 1 0 to
10,000 times more accurate as well.

Plus you have everything you want
to know about a test point, at the
push of a button, which speeds
troubleshooting tremendously.

A special Delta function even lets
you intensify parts of a waveform and
digitally measure the PPV, time or
frequency for just that waveform
section.

And it’s neat. No more tangled
leads, piles of probes or dangling
cords. The SC61 is an entire test
station in one unit.

The one and only. There are other
scopes with digital readout, but none
of them completely automate every
conventional scope measurement so
you can automatically analyze any
waveform without counting one
single graticule. Totally automatic
waveform analyzing at the push of a
button. It will make all the difference
in your productivity.

Double your productivity. When
we say the SC61 will double your
productivity, we’re being
conservative. We've seen cases of

three, four, even fen time increases
in productivity with this first-of-its-
kind, automated oscilloscope. Every
situation is different, however, so try
the SC61 and judge for yourself.
Here’s our offer.

Money back guarantee. If the
SC61 does not at least double your
productivity during the first thirty
days, you may return it for a full
refund, including freight both ways.

Call today. Get the entire SC61
Waveform Analyzer story. Call toll-
free today, and ask for our eight page
color brochure. It could be the most
productive call you make this year!

Phone Toll-Free
1 - 800 - 843-3338

Alaska, Hawaii, Canada and
South Dakota call collect
( 605 ) 339-0100

3200 Sencore Drive, Sioux Falls, $D 57107

CIRCLE 70 ON FREE INFORMATION CARD
CIRCLE 71 FOR DEMONSTRATION

RADIO-ELECTRONICS

ULTRA

Diskettes

Now... Diskettes you can
swear by, not swear at.

Lucky for you, the diskette buyer, there are many diskette
brands to choose from. Some brands are good, some not
as good, and some you wouldn’t think of trusting with even
one byte of your valuable data. Sadly, some manufacturers
have put their profit motive ahead of creating quality
products. This has resulted in an abundance of low quality
but rather expensive diskettes in the marketplace.

A NEW COMPANY WAS NEEDED AND STARTED

Fortunately, other people in the diskette industry recog-
nized that making ultra-high quality diskettes required the
best and newest manufacturing equipment as well as the
best people to operate this equipment. Since most manu-
facturers seemed satisfied to give you only the everyday
quality now available, an assemblage of quality con-
scious individuals decided to start a new company to give
you a new and better diskette. They called this product the
Ultra diskette, and you’re going to love them. Now you
have a product you can swear by, not swear at.
HOWTHEY MADE THE BEST DISKETTES EVEN BETTER
The management of Ultra Magnetics then hired all the top
brains in the diskette industry to make the Ultra product.
Then these top bananas (sometimes called floppy freaks)
created a new standard of diskette quality and reliability.
To learn the “manufacturing secrets” of the top diskette
makers, they’ve also hired the remaining “magnetic media
moguls” from competitors such as Verbatim, Memorex,
Dysanand many more. Then all these top-dollar engineers,
physicists, research scientists and production experts (if
they’ve missed you, send in your resume to Ultra) were
given one directive.. .to pool all their manufacturing know-
how and create a new, better diskette.

HOW ULTRA DISKETTES ARE MANUFACTURED

The Ultra Magnetics crew then assembled the newest, totally
quality monitored, automated production line in the industry.
We know that some of Ultra’s competitors are still making
magnetic media on equipment that is old enough to vote.
Since all manufacturing equipment at Ultra is new, it’s easy
for Ultra to consistently make better diskettes. You can
always be assured of ultra-tight tolerances and superb
dependability when you use Ultra. If all this manufacturing
mumbo-jumbo doesn’t impress you, we’re sure that at least
one of these other benefits from using Ultra diskettes will:

1 . TOTAL SURFACE TESTING - For maximum reliability, and to lessen the likelihood of
disk errors, all diskettes must be totally surface tested. At Ultra, each diskette is 100%
surface tested. Ultra is so picky in their testing, they even test the tracks that are in
between the regular tracks.

2. COMPLETE LINE OF PRODUCTS - For a diskette to be useful to you and your
computer, it must be compatable physically. Ultra Magnetics has an entire line of 5V4-inch
and 8-inch diskettes.

3. SPECIALLY LUBRICATED DISK - Ultra uses a special oxide lubricant which is added
to the base media in the production of their diskettes. This gives you a better disk drive
head to media contact and longer head and disk life.

4. HIGH TEMPERATURE/LOW-MARRING JACKET - A unique h[gh temperature and
low-marring vinyl jacket allows use of their product where other diskettes won’t work. This
special jacket is more rigid than other diskettes and helps eliminate dust on the jacket.

5. REINFORCED HUB RINGS - Standard on all Ultra mini-disks, to strengthen the center
hub hole. This increases the life of the disk to save you money and increase overall
diskette reliability.

6. DISK DURABILITY- Ultra disks will beat all industry standards for reliability at well over
millions and millions of revolutions. They are compatible with all industry specifications as
established by ANSI, ECMA, ISO and JIS.

7. CUSTOMER ORIENTED PACKAGING - All Ultra disks are packaged 10 disks to a
carton and 1 0 cartons to a case. The economy bulk pack is packaged 1 00 disks to a case
without envelopes or labels.

8. LIFETIME WARRANTY - If all else fails, remember, all disks made by Ultra Magnetics,
(except bulk pack) have a lifetime warranty. If your Ultra disks fail to meet factory
specifications, Ultra Magnetics will replace them under the terms of their warranty.

9. SUPERB VALUE - With Ultra’s automated production line, high-quality, error-free disks
are yours without high cost.

SAVE ON ULTRA DISKETTES

Product Description

Part#

CE quant.
100 price
per disc ($)

8" SSSD IBM Compatible (128 B/S, 26 Sectors)

81726

1.99

8" SSDD IBM Compatible (128 B/S, 26 Sectors)

81701

2.49

8” DSDD Soft Sector (Unformatted)

82701

3.19

8" DSDD Soft Sector (1024 B/S, 8 Sectors)

82708

3.19

5V4"

SSSD Soft Sector w/Hub Ring

50001

1.79

5V4"

Same as above, but bulk pack w/o envelope

00153

1.39

5V4"

SSSD 10 Hard Sector w/Hub Ring

50010

1.79

5V4 /#

SSSD 1 6 Hard Sector w/Hub Ring

50016

1.79

5V4"

SSDD Soft Sector w/Hub Ring

51401

1.89

5V4''

Same as above, but bulk pack w/o envelope

00096

1.49

5V4"

SSDD 10 Hard Sector w/Hub Ring

51410

1.89

5V4"

SSDD 16 Hard Sector w/Hub Ring

51416

1.89

5V4"

DSDD Soft Sector w/Hub Ring

52401

2.79

5V4"

Same as above, but bulk pack w/o envelope

00140

2.39

5 Vi"

DSDD 10 Hard Sector w/Hub Ring

52410

2.79

5V4"

DSDD 16 Hard Sector w/Hub Ring

52416

2.79

5V4"

SSQD Soft Sector w/Hub Ring (96 TPI)

51801

2.49

51/4" DSQD Soft Sector w/Hub Ring (96 TPI)

52801

3.49

SSSD = Single Sided Single Density; SSDD = Single

Sided Double Density;

DSDD = Double Sided Double Density; SSQD= Single Sided Quad Density;
DSQD = Double Sided Quad Density; TPI — Tracks per inch.

For less than 100 diskettes, add 10% to our quantity 100 price.

For additional compatibility info call Ultra Magnetics at 408-728-7777.

The Small Print

To get the fastest delivery from CE of your Ultra computer products, send or phone your
order directly to our Computer Products Division. Be sure to calculate your price using the
CE prices in this ad. Michigan residents please add 4% sales tax or supply your tax I.D.
number. Written purchase orders are accepted from approved government agencies and
most well rated firms at a 30% surcharge for net 30 billing. All sales are subject to
availability, acceptance and verification. All sales are final. Prices, terms and speci-
fications are subject to change without notice. All prices are in U.S. dollars. Out of stock
items will be placed on back order automatically unless CE is instructed differently. Min-
imum prepaid order $50.00. Minimum purchase order $200.00. International orders are
invited with a $20.00 surcharge for special handling in addition to shipping charges. All
shipments are F.O.B. Ann Arbor, Michigan. No COD’s please. Non-certified and foreign
checks require bank clearance.

For shipping charges add $8.00 per case or partial-case
of 1 00 8-inch discs or $6.00 per case or partial-case of 1 00
5V4-inch mini-discs for U.P.S. ground shipping and handling in
the continental United States.

Mail orders to: Communications Electronics, Box 1002,
Ann Arbor, Michigan 48106 U.S.A. If you have a Master Card
or Visa card, you may call and place a credit card order. Order
toll-free in the U.S. Dial 800-521-441 4. In Canada, order toll-
free by calling 800-265-4828. If you are outside the U.S. or in
Michigan, dial 313-994-4444. Telex 810-223-2422. Order
your Ultra diskettes from Communications Electronics today.
Copyright ®1983 Communications Electronics™ Ad #050583

MEMBER

DIRECT MAIL

MARKETING ASSOCIATION

OrderToll-Free! ULTRA.

800-521-4414 ^gnctics

In Michigan 313-994-4444 diskettes

COMMUNICATIONS

ELECTRONICS”

Computer Products Division

854 Phoenix □ Box 1002 □ Ann Arbor, Michigan 48106 U.S.A.

Call TOLL-FREE (800) 521 -441 4 or outside U.S.A. (31 3) 994-4444

CIRCLE 4 ON FREE INFORMATION CARD

THE MAGAZINE FOR NEW
IDEAS IN ELECTRONICS

Radio-

Electiwlac

Electronics publishers since 1908

SPECIAL FEATURE

ALL ABOUT AUTOMOTIVE NAVIGATION SYSTEMS

Computer-aided navigation is expected to play a big part in the
car of the future. But, as this report shows, that future is not all

that far away. Danny Goodman

BUILD THIS

EXPAND YOUR TIMEX/SINCLAIR OPERATING SYSTEM

Upgrade your computer with 8K of battery-backed-up CMOS

RAM. Paul W.W. Hunter

TALKING ALARM CLOCK

Part 2. With this fun project you’ll never have to tell time again.

Lee Glinski

DIGITAL VOLTMETER FOR YOUR CAR’S DASHBOARD

This easy-to-build project helps keep an eye on your car’s elec-
trical system. Fred L. Young Sr. and Fred L. Young Jr.

TECHNOLOGY

VIDEO ELECTRONICS

Tomorrow’s news and technology in this quickly changing industry.

David Lachenbruch

SATELLITE/TELETEXT NEWS

The latest happenings in communications technology.

Gary H. Arlen

VIDEOGAMES

A new generation of videogames. Danny Goodman

USING LORAN-C FOR TIME AND FREQUENCY CALIBRATION

All about the Loran-C navigational system and how it works.

R.W. Burhans

CIRCUITS AND

TRANSCONDUCTANCE OPERATIONAL AMPLIFIERS

COMPONENTS

What they are, and some practical examples of how to use them.

Thomas Henry

HOW TO DESIGN ANALOG CIRCUITS

An in-depth look at positive- and negative-feedback circuits.

Manny Horowitz

NEW IDEAS

An award-winning project from one of our readers

HOBBY CORNER

Some questions from the mailbag. Earl “Doc” Savage, K4SDS

DRAWING BOARD

More on voltage regulators. Robert Grossblatt

STATE OF SOLID STATE

Power MOSFET amplifiers. Robert F. Scott

VIDEO

SERVICE CLINIC

A dish full of bugs. Jack Darr

SERVICE QUESTIONS

R-E’s Service Editor solves technicians’ problems.

RADIO

COMMUNICATIONS CORNER

Communications and the disabled. Herb Friedman

COMPUTERS

COMPUTER CORNER

What’s new in microcomputers. Les Spindle

EQUIPMENT

Philips Model PM 3215 50-MHz Dual-Trace Oscilloscope

REPORTS

Vector PI 84-7 Slit-N-Wrap Tool

Kensington Microware System Saver Protection

Device for Apple II Computers

Soar Corporation 8050 Digital Multimeter

DEPARTMENTS 8

Advertising and Sales Offices

106

Market Center

136

Advertising Index

New Books

137

Free Information Card

New Products

Letters

What’s News

JULY 1983 Vol. 54 No. 7

ON THE COVER

To most drivers, one of the most ex-
asperating experiences is getting
lost in completely unfamiliar terri-
tory. But an independent California
inventor and a giant Japanese auto-
mobile manufacturer are hard at
work trying to make that situation a
thing of the past. If their efforts are
successful, it won’t be long until a
common automotive accessory will
be a navigational computer com-
plete with a video display. This
month, we’ll preview the future and
take a look at both systems. The
story begins on page 43.

This upgrade for the Timex/Sinclair 1000 adds
8K of non-volatile RAM. The add-on can be used
to increase the system/user memory, or more
usefully, for the permanent storage of machine-
language routines— thus, in effect, expanding
the operating system. Find out more about it
starting on page 47.

COMING NEXT MONTH
On Sale July 19

A special section devoted to elec-
tronics and photography. Among
the things we’ll look at are:

• The Sony Mavica system

• Autofocus and autoexposure
electronics

• Electronics in the darkroom
And lots more!

Radio-Electronics, (ISSN 0033-7862) Published monthly
by Gernsback Publications, Inc., 200 Park Avenue South,
New York, NY 10003. Second-Class Postage Paid at New
York, N.Y. and additional mailing offices. One-year subscrip-
tion rate: U.S.A. and U.S. possessions. $14.97, Canada,
$17.97. Other countries, $22.47 (cash orders only, payable
in U.S.A. currency.) Single copies $1.50. © 1983 by Gerns-
back Publications, Inc. All rights reserved. Printed in U.S.A.

Subscription Service: Mail all subscription orders,
changes, correspondence and Postmaster Notices of un-
delivered copies (Form 3579) to Radio-Electronics Sub-
scription Service, Box 2520, Boulder, CO 80322.

A stamped self-addressed envelope must accompany all
submitted manuscripts and/or artwork or photographs if their
return is desired should they be rejected. We disclaim any
responsibility for the loss or damage of manuscripts and/or
artwork or photographs while in our possession or otherwise.

As a service to readers, Radio-Electronics publishes available plans or information relating to newsworthy products, techniques and scientific and technological developments.
Because of possible variances in the quality and condition of materials and workmanship used by readers, Radio-Electronics disclaims any responsibility for the safe and proper
functioning of reader-built projects based upon or from plans or information published in this magazine.

JULY 1983

RADIO-ELECTRONICS

VIDEO ELECTRONICS

DAVID LACHENBRUCH

CONTRIBUTING EDITOR

New VCR A new VCR standard that eventually is expected to replace the three current half-inch home
QtsmHnrH ^ ormats (Beta, VHS, and the European Video 2000) has been approved by a Standardization
olaMUara Conference of 122 Japanese, European, and American companies, whose representatives
have been meeting in Tokyo for more than a year.

The new “8mm Video” standard was established to avoid the Beta-vs.-VHS problem that
has plagued the home-VCR industry since its inception. In order to avoid disrupting the
market, member companies, in the past, have insisted that the new standard was designed
only for use in portable camera-VCR combinations; but with the issuance of the specifica-
tions, many conference members have dropped that pose. Although initially the system is
designed to record for only 90 minutes on one cassette (in the NTSC color system), the
standard is obviously flexible enough to accommodate much longer recording times.

The recording medium is an 8-mm-wide cassette tape. The cassette itself measures
95 x 62.5 x 15-mm, slightly smaller in length and width than a standard audio cassette and
just a touch thicker than the thickest part of such a cassette. The tape can be either the
metal-powder or metal-evaporated type, and the system uses helical scan with a head drum
40mm in diameter.

Three separate audio systems are specified in the new 8mm specifications — a standard
longitudinal track, an FM-stereo helical system multiplexed with the video signal of the type
used in Beta Hi-Fi recorders, and a helical PCM (Pulse Code Modulation) track. The FM
sound system is compulsory, the other two optional. A cue track is also reserved.

The cassette itself is designed for maximum simplicity and low cost, without tape guides
and with a wide mouth to accommodate many different loading systems. It has two lids to
keep out dust, and recognition holes for automatic detection of tape type and thickness, as
well as grips for an auto-changer.

Sources in the Standardization Conference say that an increase in recording time to four
hours by means of slower tape speed and thinner tape is easily possible now. Development in
the future of new heads and new tape formulations (including the perpendicular or vertical-
domain recording system, now in advanced stages of development) will make possible
further increases in record/play time.

In Japan, there are widespread forecasts that 8mm VCR’s will begin to appear before the
year is over, but in any event the American market could see the first portables in 1984.
Assuming that longer-playing versions are approved by the Standardization Conference,
home decks could show up in about three years, and at that point the new format should begin
to take over from Beta and VHS.

The 8mm standard was approved by the conference for both NTSC and PAL color systems,
with different parameters — the PAL version has a record/play time of one hour. At the last
minute, France’s Thomson-CSF proposed that a baseband recording system, “timeplex,” be
used for any SECAM models. Therefore the conference approved no SECAM standard, but
earmarked the French proposal for further study.

The agreement on a new standard format has great implications on the future of the entire
video field, laying the groundwork for a new, far more flexible and potentially lower-cost
system and eventually ending the standards war.

DIGITAL TV It can now be definitely reported that color-TV sets using all-digital signal processing will be
available, at least in token quantities, in 1984. In the United States, they’re expected to be
available from General Electric and Zenith, with offerings also possible from Sharp and Sony.
All are customers of ITT for its set of seven VLSI digital IC’s. The first digital sets may well be in
the form of component TV, because they will be designed for add-ons to make possible
features not available with analog TV’s. One of the first add-ons is expected to be a ghost
eliminator. The new digital TV’s also are expected to enhance the capabilities of home
computers (since they are essentially computers themselves). With the development of
low-cost frame-store accessories, the digital TV’s will have the potential ability to simulate
high-definition television by doubling the number of lines in the picture, inserting “derived”
lines between the transmitted ones. Other features could be stop-motion and picture-in-
picture (for viewing two channels simultaneously). While digital sets are imminent, those
special effects probably won’t be along for several years. r-e

“I built this 16-bit computer and
saved money. Learned a lot, too.”

Save now by building the Heathkit H-100
yourself. Save later because your computer
investment won’t become obsolete for
many years to come.

Save by building it yourself. You can save hundreds of
dollars over assembled prices when you choose the new
H-100 1 6- Bit/8- Bit Computer Kit — money you can use
to buy the peripherals and software of your choice.

The H-100 is easv to build - the step-by-step Heathkit
manual shows you how. And every step of the way, you
have our pledge - "We won’t let you fail." Help is as close
as your phone, or the nearest Heathkit Electronic Center.'!'

And what better way to learn state-of-the-art computing
techniques than to build the world’s only 16-bit/8-bit
computer kit? To run today’s higher-speed, higher-per-
formance 16-bit software, you need an H-100. It makes a
big difference by processing more data faster.

Dual microprocessors for power and compatibility. The
H-100 handles both high-performance 16-bit software
and most current Heath/Zenith 8-bit software.

Want room to grow? The H-IOO’s standard 128K byte
Random Access Memory complement can be expanded
to 768K bytes compared to a 64K standard for many
desktop computers.

And the industry-standard S-100 card slots support
memory expansion and additional peripheral devices,
increasing future upgradability of the H-100.

High-capacity disk storage, too. The H-IOO’s 5.25"floppy
disk drive can store 320K bytes on a single disk. The
computer also supports an optional second 5.25 'and
external 8" floppy disk drives. And an optional internal
Winchester disk drive will be available soon.

For more information, circle the reader service number
below. Better yet, visit your Heathkit Electronic Center for
a demonstration!

128K bytes standard.
Optional.

The H-100 gives me the most
for my computer dollar!

Heathkit

Company

Heathkit Electronic Centers are units of Veritechnology Electronics Corporation.

Heath Company and Veritechnology Electronics Corporation are subsidiaries of Zenith Radio Corporation.

CIRCLE 16 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

WHAT'S NEWS

Cellular radio system
to begin in U.S.A.

The FCC has allocated 666
channels to a new “cellular” two-
way radio service, which, with its
greatly more efficient use of the
radio spectrum than the current
mobile telephony system, will
make a car telephone available to
anyone almost anywhere in the
United States.

In a cellular system, an area
such as a city is not covered with a
single high-powered transmitter,
as is done today. Instead, the area
is divided up into sections, or
“cells,” each with a low-power
transmitter whose range is pretty
much limited to the area of the cell.
Since adjacent cells are on non-
interfering frequencies, the same
frequency can be “re-used” for
several widely separated cells in a
large city or metropolitan area, in-
creasing greatly the number of
phone calls that may be handled in
a given area.

The FCC opened applications
for cellular system licenses, and as
of March, 1983, had already
granted permits to cellular mobile

telephone systems in nine U.S.
metropolitan areas. Service is ex-
pected to start within two years.

A cellular system is made up of
four elements (plus the regular
telephone system). Those are the
Mobile Telecommunications
Switching Office (MTSO); a base
station (transmitter/receiver), with
its antennas, in each cell; wire or
microwave connecting links be-
tween base stations and the
MTSO, and the mobile radios,
which may be vehicle-mounted or
hand carried.

When a telephone user wishes
to make a call, he simply dials the
number of the mobile subscriber,
as he would any other call. (He
need know nothing of the where-
abouts of the car he is calling.) The
call then goes to the mobile unit’s
MTSO, which sends a paging sig-
nal over all the base stations in the
area. The mobile unit, which moni-
tors a nearby base station con-
tinuously, responds automatically
to the paging signal and es-
tablishes contact with the base sta-
tion. The MTSO then switches the
call to one of the traffic channels of

that base station, and the subscrib-
er’s phone rings.

If the mobile subscriber travels
out of the cell during a call, com-
munications are automatically
switched over to the base station of
the cell into which he moves.

The subscriber in a mobile vehi-
cle simply dials the number he
wants, as he would on his home
phone.

The service is expected to cost
subscribers anywhere from $75 to
$150 per month. That would in-
clude an access fee of between
$10 and $50 per month, plus
charges for actual use. Those
might run from 1 2 cents per minute
in off-peak hours to 40 cents per
minute in peak periods.

OK Industries forms
electronics division

OK Industries, a New York-
based manufacturer of production
equipment for the electronics and
telecommunications industries,
has formed an Electronics Divi-
sion. The new division is putting
out a broad range of bench and

field test instruments, with the idea
of offering “truly superior lab-
quality instruments at prices within
the reach of even the ‘smallest’
user.”

The first product from the new
division is a 1 -MHz function gener-
ator with both frequency and am-
plitude modulation; it will sell at
$250.

900-MHz personal radio
may be on the way

The FCC has issued a Notice of
Proposed Rulemaking to imple-
ment a new personal radio-
communications service (PRCS),
proposed by General Electric, in
the 900-MHz frequency band. G.E.
hopes that the FCC will issue a
Final Report and Order within the
next few months.

The FCC proposal is for a sys-
tem that will consist of a base sta-
tion connected to the telephone
network, and one or more units
that can be installed in cars. The
user in a car will then be able to
place calls to any telephone, or be
reached in the car from any tele-
phone, provided he is within the
system’s range.

The FCC notice proposes to set
aside 8 MHz in the 900-MHz band
for the new service. That reserva-
tion would permit 133 channels of
30 kHz each for two-way PRCS
communications.

New TV space camera

RCA has developed a new tele-
phone camera tube that can detect
objects the size of a soccer ball
22,000 miles away.

Serving as the “eye” of a special
camera of the Ground-based
Electro- Optical Deep Space Sur-
veillance System (GEODSS), it
can see objects 10,000 times
dimmer than the faintest ones vis-
ible to the naked eye.

The new Silicon-/ntensifier Tar-
get (SIT) tube, type C21146H, is
the largest of its type that RCA has
ever made. Its 32mm of usable
area is twice that of the targets now
used in the surveillance cameras
that provide the resolving capabil-
ity of the GEODSS equipment. The
target has four times as many sili-
con diodes as older types.

The GEODSS system answers
the need for advanced tracking
continued on page 8

CELLULAR NETWORK OVER PART OF A CITY. The call is routed from the caller’s home via the local telephor
exchange to the Mobile Telecommunications Switching Office, a complex automatic device that locates the car, maki
the connection, and then switches the call from cell to cell as the car moves through the area.

TdlZ OOnn MULT| - PURP0SE THE PERFORMANCE/

I lzr\ ^.£UU OSCILLOSCOPES PRICE STANDARD

Now. Tektronix 60 MHz Performance
is just a free phone call away!

Wide-range verti- Two high-sensitivity

cal sensitivity: channels: dc to 60

Scale factors from MHz bandwidth

100 V/div (10X from 10 V/div to 20

probe) to 2 mV/div mV/div; extended

(IX probe). Accurate sensitivity of 2

to ±3%. Ac or dc mV/div at >50

coupling. MHz.

Sweep speeds: Delayed sweep

from 0.5 s to 50 ns. measurements:
To 5 ns/div with XI 0 Accurate to r3%
magnification. with single time-

base 2213; to
:r1.5% with dual
time-base 2215.

Complete trigger Probes included,

system. Includes High-performance,

TV field, normal, positive attachment

vertical mode, and 10-14 pF and 60

automatic; internal, MHz at the probe

external and line tip.

sources; variable
holdoff.

These easy to order scopes are
proof that it’s not expensive to
have advanced, 60 MHz perform-
ance from Tektronix on your
bench. It’s just practical! Feature
for feature, the Tek 2213 and 2215
set a price/performance standard
unmatched among portable scopes.
And are backed by the industry’s
first three-year warranty on all labor
and parts, including the CRT.

So advanced they cost you
less: $1200* for the 2213! $1450*
for the dual time base 2215!

These low costs are the result of a
new design concept that utilizes

fewer mechanical parts than any
other scope.

Yet there’s no scrimping on per-
formance and reliability. You have
the bandwidth for digital and analog
circuits. The sensitivity for low signal
measurements. The sweep speeds
for fast logic families. And delayed
sweep for fast, accurate timing
measurements.

Scope. Probes. Three-year
warranty and expert advice. One
free call gets it all! You can order,
or obtain literature, through the
Tektronix National Marketing Center.
Technical personnel, expert in oscil-

loscope applications, will answer
your questions and can expedite
delivery. Direct orders include
probes, operating manuals, 15-day
return policy, full Tektronix warranty
and worldwide service back-up.

Order toll free:
1 - 800 - 426-2200
Extension 12

In Oregon call collect:
(503) 627-9000 Ext. 12

'Price FO.B. Beaverton, OR. Price subject to change.

Ttektronix

COMMITTED TO EXCELLENCE

CIRCLE 74 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

WHAT'S NEWS

Cellular radio system
to begin in U.S.A.

The FCC opened applications
for cellular system licenses, and as
of March, 1983, had already
granted permits to cellular mobile

telephone systems in nine U.S.
metropolitan areas. Service is ex-
pected to start within two years.

that base station, and the subscrib-
er’s phone rings.

If the mobile subscriber travels
out of the cell during a call, com-
munications are automatically
switched over to the base station of
the cell into which he moves.

The subscriber in a mobile vehi-
cle simply dials the number he
wants, as he would on his home
phone.

OK Industries forms
electronics division

How cellula
^telephone
works:

lOCAL^**

TELEPHONE

.OFFICE

CALLER

MOBILE

SWITCHING

OFFICE

CELLULAR NETWORK OVER PART OF A CITY. The call is routed from the caller’s home via the local telephone
exchange to the Mobile Telecommunications Switching Office, a complex automatic device that locates the car, makes
the connection, and then switches the call from cell to cell as the car moves through the area.

field test instruments, with the idea
of offering “truly superior lab-
quality instruments at prices within
the reach of even the ‘smallest’
user.”

The first product from the new
division is a 1 -MHz function gener-
ator with both frequency and am-
plitude modulation; it will sell at
$250.

900-MHz personal radio
may be on the way

The FCC notice proposes to set
aside 8 MHz in the 900-MHz band
for the new service. That reserva-
tion would permit 133 channels of
30 kHz each for two-way PRCS
communications.

New TV space camera

RCA has developed a new tele-
phone camera tube that can detect
objects the size of a soccer ball
22,000 miles away.

Serving as the “eye” of a special
camera of the Ground-based
Electro-Optical Deep Space Sur-
veillance System (GEODSS), it
can see objects 10,000 times
dimmer than the faintest ones vis-
ible to the naked eye.

The GEODSS system answers
the need for advanced tracking
continued on page 8

TEK 2200

MULTI-PURPOSE

OSCILLOSCOPES

THE PERFORMANCE/
PRICE STANDARD

Now. Tektronix 60 MHz Performance
is just a free phone call away!

Sweep speeds:

from 0.5 s to 50 ns.

Delayed sweep
measurements:

Complete trigger
system. Includes
TV field, normal,
vertical mode, and
automatic; internal
external and line
sources; variable
holdoff.

Probes included.

High-performance,
positive attachment
10-14 pF and 60
MHz at the probe
tip.

Tektronix 2213

Wide-range verti-
cal sensitivity:

Scale factors from
100 V/div (10X
probe) to 2 mV/div
(IX probe). Accurate
to ±3%. Acordc
coupling.

Two high-sensitivity
channels: dcto 60
MHz bandwidth
from 10 V/div to 20
mV/div; extended
sensitivity of 2
mV/div at > 50

So advanced they cost you
less: $1200* for the 2213! $1450*
for the dual time base 2215!

These low costs are the result of a
new design concept that utilizes

fewer mechanical parts than any
other scope.

Order toll free:
1-800-426-2200
Extension 12

In Oregon call collect:
(503) 627-9000 Ext. 12

*Price FO.B. Beaverton, OR. Price subject to change. —

Tektronix

COMMITTED TO EXCELLENCE

CIRCLE 74 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

WHAT'S NEWS

continued from page 6

methods. That need is caused by
the ever-increasing number of ob-
jects in space. (An estimated
15,000 pieces — satellites and
debris — are now drifting in orbit.) It
uses two 40-inch telescopes for
deep space tracking and a 1 5-inch
instrument for scanning lower alti-
tudes. Each telescope is coupled
to a camera containing one of the
new low-light-level SIT camera
tubes.

Pictures from the TV cameras
are converted into digital pulses
and fed into a computer, which ex-
amines the data to sort out stars
from moving objects. The compu-
ter software also contains a cata-
log of known stars and orbiting sat-
ellites for identification and loca-
tion purposes.

Class A power amplifier
for car stereo

Visonik of America, Inc., a
manufacturer and distributor of
automotive-sound products, has
introduced the first Class-A power
amplifier specifically intended for
car-stereo applications. That
amplifier, the model A265, boasts
an output of 65 watts-per-channel
with total harmonic distortion
claimed to be less than 0.01 % from
20 Hz to 20 kHz.

The chief advantage Class-A
operation is that it eliminates the
distortion introduced by the push-
pull action of more conventional
Class-B amplifiers. Among the
unit’s circuit features are full com-
plementary symmetry, just 30 dB
of negative feedback, and a wide
open-loop bandwidth for a high
slew-rate and low TIM distortion.
The amplifier also includes an ex-
clusive Perma-Tect circuit. That
circuit monitors the output current
and voltage across the output tran-
sistors; and, should those levels
become excessive, the circuit
limits the power without interfering
with the signal. In addition, the
amplifier has thermal breakers to
prevent overheating. According to
a company spokesman, that com-
bination makes the amplifier “vir-
tually unblowable.”

The A265 offers a variable low-
level (100-550mV) input for use
with almost any program source. A
Molex harness is included for easy
installation.

Sanyo LCD TV

Sanyo has developed 3 and 4-
inch liquid crystal TV’s, using a
newly developed liquid-crystal dis-
play (LCD) and amorphous silicon
thin-film transistors (aSiTFT) that

are designed for switching.

The display on the 4-inch model
is 60 x 80 mm (about 2% x 5%2
inches) and exterior dimensions
are 253 x 30 x 1 1 3 mm (approx-
imately 10 x 1 %2 x 4 15 / 3 2
inches) — truly pocket sized.

The new switching transistor is
said to provide greater reliability
than previous approaches, and the
new TN (twisted nematic mode)
crystal produces better contrast
and a wider view angle. The dis-
play boasts are 220 x 240 pixels.

The liquid-crystal displays are
being rapidly developed for use in
TV sets, office machines, etc., but
picture clarity and driving systems
remain problems.

“Telephone on an chip”

High reliability and reduced
component count are among the
features of the new telephone
technology introduced by Amer-
ican Telecommunications
Corporation, a subsidiary of Corn-
dial. ATC is a supplier of tele-
phones, answering machines, and
automatic dialers to the Bell sys-
tem, as well as to major in-
dependent telephone companies
and retailers.

Evidence of that new technology
can be seen in two ATC products.
The Allegro is a compact residen-
tial phone that features a 10-
number memory dialer, automatic
redial, and a true hold button. The
other new phone, the Voice Ex-
press 41 is designed for business
applications. It combines an im-
proved speakerphone, a 41-
number automatic dialer, clock,
call timer, and security features.
Both phones incorporate a new 1C
that is essentially a complete tele-
phone. That 1C is part of ATC’s
effort to reduce the cost and com-
plexity of manufacturing tele-
phones that meet Bell-system
standards.

According to Robert E. Lee, ATC
Vice President of Engineering, the
company’s goal is to totally auto-
mate telephone assembly. By us-
ing sophisticated robots to assem-
ble the telephones, Comdial hopes
to obtain the distinct technology
and cost advantage it feels is
needed to compete with imported
low-cost, and often lower-quality,
telephones. R-E

THE ALPHASONIK A265 Class-A power amplifier delivers 65 watts-per-
channel into a 4-ohm load. It features Visonik’s exclusive Perma-Tect protec-
tion circuitry.

Radia

Electronics

Hugo Gernsback (1884-1 967) founder
M. Harvey Gernsback, editor-in-chief
Larry Steckler, CET, publisher
Arthur Kleiman, editor
Josef Bernard, K2HUF, technical
editor

Carl Laron, WB2SLR, associate
editor

Brian C. Fenton, assistant editor
Jack Darr, CET, service editor

Robert F. Scott, semiconductor
editor

Herb Friedman, communications
editor

Gary H. Arlen, contributing editor

David Lachenbruch, contributing
editor

Earl “Doc” Savage, K4SDS, hobby
editor

Danny Goodman, contributing editor

Dan Rosenbloom, production
manager

Robert A. W. Lowndes, production
associate

Joan Roman, circulation director

Arline R. Fishman,

advertising coordinator

Cover photo by Robert Lewis

Radio-Electronics is indexed in Ap-
plied Science & Technology Index and
Readers Guide to Periodical Literature.

Gernsback Publications, Inc.

200 Park Ave. South
New York, NY 10003
President: M. Harvey Gernsback
Vice President; Larry Steckler

ADVERTISING SALES 212-777-6400

Larry Steckler
Publisher

EAST/SOUTHEAST

Stanley Levitan
Radio-Electronics
200 Park Ave. South
New York, NY 10003

212- 777-6400

MIDWEST/Texas/Arkansas/Okla.

Ralph Bergen

Radio-Electronics

540 Frontage Road— Suite 325

Northfield, Illinois 60093

312-446-1444

PACIFIC COAST
Mountain States

Marvin Green
Radio-Electronics
413 So. La Brea Ave.

Los Angeles, Ca 90036

213- 938-0166-7

YOU SELECT FULL MANUAL
OR FULL AUTORANGING

OTHER NEW
DMM MODELS
PRICED
FROM
$75.00

EASY TO USE... RELIABLE
SINGLE-ROTARY SWITCH
CONTROL

• « TO

MODEL 2816

500 HOUR BATTERY LIFE

HIGH CONTRAST LCD
SHOWS MEASUREMENT
AND FUNCTION

0.25% dc volt
accuracy

Continuity beeper
Diode test

Transient and
overload protected

High energy fuse

New! A digital
multimeter that
lets you choose
autoranging
1 convenience or
> v manual control

•j

and the o
DMMs, s<
[1 312 8,

International Sales, 6460 W. Cortland St., Chicago, Illinois 60635
• Canadian Sales; Atlas Electronics, Ontario
South and Central American Sales, Empire Exporters, Plainview, NY 11803

RADIO-ELECTRONICS

SATELUTE/TELETEXT NEWS

GARY ARLEN

CONTRIBUTING EDITOR

TELETEXT

DECODERS

The CBS Television Network has started a teletext service called Extravision. The service will
be broadcast by the almost 200 CBS affiliated stations (90 percent as this is being written),
making it the first national broadcast teletext service. Extravision transmits 100 pages of
national and local information and advertising as well as closed captioning of some programs.
The service uses the North American Broadcast Teletext Standard (NABTS).

Time Inc. and Matsushita Electric Industrial Co. (Panasonic) have signed a “long-term
technology agreement” under which the two companies will co-develop hardware for home-
information systems. The first such product is a low-cost decoder for Time’s teletext service —
with the hoped-for $1 50 device being offered under the Panasonic name. The first test models
of the unit will be available late this year, with production runs set to begin in 1984 at
Matsushita’s automated color-TV factory in Japan.

The teletext decoder will use the “North American Broadcast Teletext Specification,” the
technical format that Time Inc., CBS, NBC and A.T.&T. have adopted. It will be able to pickup
Time’s full-channel teletext feed, now being tested, as well as vertical blanking-interval
teletext, such as the feeds being planned by the television networks. The decoder will include
an extension unit to permit add-ons such as a full alphanumeric keyboard, printer, and floppy
disks for data storage. In addition, the terminal can accommodate joysticks for videogames,
an audio cassette recorder, and a modem for two-way service.

The decoder will also be able to handle software for the customized information services
that Time plans to transmit. The decoder’s interactive capability makes faster access possi-
ble, and the unit will include provisions that allow it to be used for general-purpose computing.
Time’s teletext service will be offered to cable TV systems, starting with companies operated
by its subsidiary American TV and Communications. In addition to news and other typical
information services, Time’s teletext project includes a variety of innovative recreational
activities that take advantage of the high-quality graphics of the technology. For example, a
youth-oriented section of the service includes an electronic version of “Mr. Potatohead,” that
allows children to compose a face by selecting features they would like to insert and placing
them over the face outline on the TV screen.

VCR’S AND
TELETEXT

EECO (1 601 E. Chestnut Ave., Santa Ana, CA 92701 ), a California company that produces
tape-editing equipment and mini-computer systems, is testing Pictureware, a system that will
permit home videocassette-recorders to record and transmit videotex or teletext signals.
Pictureware is an interactive still-frame video technology that uses a VCR and a decoder box
to compress images, text, and audio onto videotape; material can then be retransmitted in
high-speed bursts. The equivalent of a 100-page teletext magazine with 75 color pages of
near video-picture quality can be transmitted in about seven seconds— about the time it takes
to cycle such a group of pages through a standard vertical blanking-interval sequence. The
system becomes interactive through the use of phone lines or two-way cable. EECO sees the
target price for the decoder needed to receive the videotex and teletext signals at about $300.
A modified VCR, needed to pick up the digital data, will cost about $100 more than an
unmodified one. EECO plans to begin marketing its Pictureware system in 1984.

AROUND THE
TELETEXT
CIRCUIT

In an apparently unprecedented marketing maneuver, Zenith says its will build and sell
teletext receivers in a local market if a TV-station owner in that community commits to offering
British-format teletext for at least five years. The unusual offer would presumably encourage
broadcasters to begin a service knowing that a supply of receivers will be available in their
communities. Zenith, which has long favored the “sturdy” British technology, is presumably
also willing to deal with broadcasters working in other teletext formats. The company has
already been the primary supplier of teletext receivers for other field trials of teletext.

RCA Laboratories has received a patent for a system that will increase the legibility and
color contrast of teletext material by modifying the video signal. The system, primarily for use
in set-top teletext decoders, is said to improve color definition and clarity. R-E

A P PRODUCTS INCORPORATED • 9450 Pineneedle Drive • P. 0. Box 540* Mentor, Ohio 44060* [216] 354-2101* TWX: 810-425-2250
In Europe, contact A P PRODUCTS GmbH*Baeumlesweg 21 • D-7031 Weil 1 • West Germany

For the name of your nearest distributor call Toll Free 800-321-9668. (In Ohio call collect 216-354-2101.)

ntroducing Our Complete Line of Famous A P Quality and Price

Interconnection Products and Every A P product is built with time-proven
Accessories. ..Featuring Our New quality and dependability. And best of
lation Displacement Connectors, all.. .each one is very competitively priced,
matter what your requirements in Your Si le Source
ection products, we have just what b

looking for. DIP, Socket, and Card- A p makes hundreds of electronic circuit
C connectors, all styles and sizes of building and testing devices as well as
2rs and D-Submin in both IDC and a complete line of interconnection
jrsions. Also flat cable in both gray products and accessories. Everything from
rainbow in a wide range of widths. Breadboards, Super-Strips, Test Clips
_ ^ . , , _ , and Poweraces to Headers, Connectors

Jew Low Cost IDC Assembly Tool anc | Cable,
iationally low-priced it won't put a

"crimp'' in your budget. A P has it all for you!

RADIO-ELECTRONICS

VIDEOGAMES

Future games

DANNY GOODMAN, CONTRIBUTING EDITOR

THE ARRIVAL OF SO-CALLED THIRD-

generation home-videogame systems like
the Atari 5200 and Colecovision , plus
Coleco’s announcement of a “fourth
generation” tape-loading peripheral,
leads me to speculate about what kind of
home videogames we’re likely to be play-
ing in the late 1980’s. I’m not talking
about science-fiction gadgetry — stuff
like holographic projections coming from
your R2-D2 robot. I’m talking about the
application of technologies that we have
today, buried behind locked laboratory
doors — technology that needs only a little
refinement to be both practical and
affordable.

Interactivity between game play and
player will be the area where we will see
the greatest changes in the years ahead.
This interactivity will take many forms.

Late last year, the world was treated to
a glimpse of the interactive future when
Sega/Gremlin (555 Millrose, Los An-
geles, CA 90038) demonstrated an arcade
game that superimposed a shoot- ’em-up
space chase on a videodisc-scene back-
drop that looked like outtakes from a low-
budget Star Wars imitation. If a player
successfully hit an alien ship, the disc
would jump to a scene of an explosion in
space. The game play and background are
not particularly well integrated in this ear-
ly commercial attempt, but the concept is
a valid one.

Videodiscs, by themselves, are just
now offering interactive adventures such
as Murder, Anyone? from Vidmax (36
East 4th St., Cincinnati, OH 45202). In
that game, the viewer’s response to clues
causes the story to jump from one charact-
er’s account of the crime to another’s. As
a viewer enters a response into a remote
control keypad, the microprocessor-
controlled videodisc player accesses the
proper segment of the disc.

But that’s nothing compared to the
possibilities of integrating more tradition-
al videogame play-screens with the high-
resolution effects of a videodisc scene.
With game-console-generated graphics
linked to the videodisc frame counter
(there are 54,000 individually address-
able frames on a disc), we might have the
effect of walking down a corridor in an
adventure maze-game. Suddenly a game-
generated object — how about a treasure
chest — appears on the floor in the dis-
tance. As we walk toward it, the chest, in

FIG. 1

proper perspective, gets larger. When
we’re standing directly in front of the
chest, we have arms (from the disc) reach
down and pick it up. Together, the chest
and arms recede out of sight below the
screen as though we actually had picked it
up. Other game-generated objects could
be picked up by the same disc-generated
arms later in the game.

Another interactive trend we’ll see in-
volves increased use of our other senses.
Right now, only our senses of sight and
hearing are stimulated by a videogame.
For now, we’ll have to live with the
graphics-resolution limitations of the
home color-TV. Better-quality speech
synthesis is about all we can expect from
the current selection of systems. But
stereo sound-effects will be the next step
in attempted realism. For example, we’ll
be able to hear enemy ships approaching
from off-screen to the left or right.

Beyond that, the sense of touch opens
the way for game development into the
late 1980’s. Small solenoids will be built
into a hand controller to give your palm a
little “kick’ ’ when you catch a fly ball in a
baseball game, or vibration when you’re
at the control of a race car.

We can even see special environmental
videogame-chairs that partially enclose
us in a sensory barrage of surround sound
and that have motorized or vibrating seats
to stimulate the sensations of flying a
B-17 through flack or piloting the Mil-
lenium Falcon through hyperwarp. Most
joystick-type controls would be in the
armrests; a steering controller and two
foot-pedals would swing in front of us
from one side for games requiring that
kind of control. The enclosure could ade-
quately contain vapors from scented air

and release them in synchronization with
changing screens. For example, as you
walked through dark, musty caverns of an
adventure maze-game, only your keen
sense of smell would help you distinguish
between several look-alike scenes.

Are these ideas far fetched? Hardly.
Coleco has already demonstrated the
kicking hand controller, but decided to
hold off for a while. And a new company
in the add-on business, Amiga, has
shown a foot-operated floor controller
(the Joy board, shown in Fig. 1) that lets
you stand up and recreate the motions of
skiing down a mountain in conjunction
with a skier’s-eye-view of a slalom
course. There’s even a prototype environ-
mental chamber that spins you around and
gives you a real sense of motion as you
pilot your craft. Those are but the simple
first steps toward future homebound sim-
ulations of real-life and imagined adven-
tures.

CIRCLE 101 ON FREE INFORMATION CARD

U.S. Games (1515 Wyatt Drive, Santa
Clara, CA 95054) is dedicated to produc-
continued on page 14

U.S. Games’ Eggomania
for Atari 2600

^f^Fordham
.lowers Prices on £

PRECISION

Test Equipment

Comes With Probes

Now Fordham is passing on to customers the hugest savings
possible on test instruments. To help celebrate the opening of
our new 40,000 square foot facility on Long Island, we’ve
purchased an extra large inventory of B&K Precision products.

Autoranging DMM

Model 2845 each

Reg.-SW?^ Now ■ ^

6E3E2E0I

• Fullv automatic, auto-

ranges on all functions.

• Range lock holds any
range.

• 0.1% accuracy.

• Fast reading.

• o.5" LCD display.

• Autozeroing.

• Autopolarity on all
ranges.

• Audible continuity
indicator.

• Varistor and fuse over-
load protection.

- rf shielded.

, Meets UL 1244 safety
standards.

We’re offering the quality of name brand products and the
benefits of our volume purchasing power. While supplies last
we guarantee these unbelievably low prices.

^IT 8 ®®’ 4 Channel 100 MHz
Dual Time Base Scope

, H'n£'-:-75°cC:Now14S9^ h

BBC

• 100 M . H2 response, 3.5nS rise time e 2nS/div
sweep rate with 10X magnifier • Trigger views or
four separate inputs • Dual time base • i m nhm

mHz' #°CH° 1°freai'jT UtS * 1 mV/div sensitivity to 1 00

• Etching power supply e Selectable choo
^^^^^^^^^^^^^^utrentyDrobecalibrators.

Low Distortion
Function Generator

Model 3010
Reg

Now

s 187 *°*

• Generates sine, square and triangle
waveforms • Variable amplitude and fixed
TTL squarewave outputs • 0.1 Hz to 1 mHz
in six ranges • Typical sine wave distortion
under 0.5% from 0.1 Hz to 100 kHz • Variable
DC offset for engineering applications

• VCO external inputfor sweep-frequency tests.

i Dynapeak Tra nsisto r
Tester

Model 520B
Reg.S23e«tr

Now

s 19915 *

. Fast testing • Hi/Lo drive

circuit when oflierewont^Hdentifies^

identification. —

Reg. $405 W

Now

$ 420 7s

• each

• Restores color and
b/w picture tubes
like new! Uses the most
powerful restoration

CRT n< ? Wn with minimal dangeT

tests all thmo S ' Ve multlplex lest techr
tano . . ^ree guns of color CRTs sir

even CRTT d f: ac,Ual bating con
ZSp. CRTs w,th common G1 and ai

FOR ORDERING OR PRICING ON OTHER TEST EQUIPMENT

Call Toll Free
( 800 ) 645-9518

N.Y.S. (800)832-1446

FORDHAM

260 Motor Parkway, Hauppauge,N.Y.11788

■ Master Charge ■ VISA ■ COD

■ Money Order ■ Check

$50.00 minimum order

COD’s extra (required 25% deposit)

VfSA*

N.Y. State
residents add
appropriate

ADO FOR SHIPPING AND INSURANCE

$250.00 $4.50

$251 .00 to 500.00 0.5O

501 .00 to 750.00 8.50

751 .00 to 1000.00 12.50

over 1000.00 15.00

JULY 1983

RADIO-ELECTRONICS

VIDEOGAMES

continued from page 12

ing videogame cartridges for the entire
family to enjoy. As a result, they stay
away from the heavy artillery shoot-’ em-
up games and favor those that are easy to
grasp by inexperienced game players,
young and old. Eggomania , for one to
four players, is just such a game.

The scenario sets a turkey-like bird
scurrying from side to side along the top
of the screen. As he moves, he drops
green eggs. Each player in turn uses a
paddle controller to position a blue bear at
the bottom of the screen under each egg
and catch it in an upturned hat. Points are
scored for each egg caught. If the bear
should fail to catch an egg, the floor re-
ceives a layer of yellow egg yolk. At the
end of each wave of eggs, the tables turn
for about 15 seconds and you activate the
bear to throw eggs back at the dancing
bird. A successful hit is worth points. The
game ends when enough eggs have been
dropped for the yolk to cover up the bear
and his hat.

By keeping most of the screen black,
the game designer was able to make the
Atari 2600 present a graphically well-
detailed bird character. The bird is filled
with a variety of colors and high resolu-
tion crispness that shows up well against
the black background. When you hit the
bird with an egg, the bird loses its feath-
ers, revealing polka-dot underwear; his
top feathers turn into a beanie-like pro-
peller that help his scrawny wings lift him
up and out of the screen.

As you can see, the graphics are meant
to be entertaining. And the sound, too, is
geared toward keeping kids amused.
Three different musical tunes, intermixed
with cheeps and other bird sounds, spark
up the action in places.

One design feature of the game makes
Eggomania difficult — perhaps
frustrating — at the higher levels. You
can’t just sweep the bear and hat quickly
across the screen to catch a horizontal
string of eggs. There appears to be just a
very small zone around the hat that allows
you to catch an egg successfully. There
will be many times when you’ll think you
should have caught an egg for sure, yet
wind up knee-deep in yolk.

Eggomania begs comparison with a
similar catching game called Kaboom
from Activision. If you prefer cute music
and cartoons, then Eggomania is the one
to get. But if building game skill is your
goal, Kaboom is a better choice.

CBS Video Games’ Wizard
of Wor for Atari 2600

CIRCLE 102 ON FREE INFORMATION CARD

CBS Video Games Wizard of Wor

GRAPHICS

SOUND

EASE
OF LEARNING

CHALLENGE

VALUE

—

As versatile as the Atari 2600 has pro-
ven to be over the years, the machine has
limitations in graphics and sound. There
is only so much that even the genius game
designer will be able to accomplish with a
standard cartridge game. Wizard of Wor
from CBS Video Games (Long Meadow
Road, Hagerstown, MD 21740), is one of
those games whose ambitions fell prey to
the 2600' s stumbling blocks.

The original Wizard of Wor was a mod-
estly successful Midway arcade game of
the pr t-Pac-Man era that put great de-
mands on the player’s peripheral vision
and coordination. One or two players can
each control a “worrior” armed with a
laser blaster. Worriors search a dungeon
maze for numerous enemies, some com-
pletely visible, others visible only at
times. All enemies, whether visible or
not, are tracked on a radar screen.

Beginning with wave two, after you’ve
cleared the enemies from the dungeon,
yet another super-swift enemy, the Wor-
luk, tries to escape the dungeon, and
will — unless your worrior can shoot him
first. After that (on random waves) the

Wizard of Wor appears and hurls light-
ning bolts at your worrior. Shooting the
elusive Wizard before he escapes nets
players a dungeon-shaking graphics
display — and a ton of points.

The difficulties in putting this game
into a 2600 cartridge are many. One of the
challenging features of the original was
that in advanced waves, the maze walls
were partially invisible, leading to a suc-
cession of “pits,” or large sections of the
maze with invisible walls. In CBS’s ver-
sion, there are only two maze-layouts that
alternate between waves.

More disturbing during game play on
the CBS version is excessive flicker
caused by having so many moving objects
on the screen at once. As you slowly
eliminate enemies, the remaining images
become more solid. But until that time, it
is very difficult to keep your eye on the
dimly lit enemies and the radar screen at
the same time.

The only graphics salvation is the dis-
play when you hit the Wizard. Instead of a
colorful fireworks display, the screen
flashes in black and white for a sur-
prisingly eerie effect.

There are many other elements of the
original that were left out of the 2600
version, although they were well cap-
tured in Astrocade’s Incredible Wizard
version. But even on its own merit,
CBS’s Wizard of Wor does not contribute
to the state of the art for the latest 2600
cartridges. R-E

“Yes, I built this computer from
scratch — $1,435 worth of scratch.”

VIDEO EQUIPMENT

QUALITY • LOW PRICES
OFF-THE-SHELF DELIVERY

from FORDHAM of course.

MODEL V-1880

BP STABLIZER/IMAGE ENHANCER/RF CONVERTER/
VIDEO FADER/2-WAY DISTRIBUTION AMPLIFIER

OUR PRICE $ 135.00 each

Most versatile video processor. Contains five units in one: stabilizer (video guard
remover); image enhancer; video to RF converter; video fader; and dual output
distribution amplifier.

Stabilizer Will correct entire range of copy guard distortion such as jitter,
vertical roll or black bar travelling through picture.

Enhancer Lets you attain best picture for your own preference.

RF Converter Allows your TV set to receive video and audio signals from your
image enhancer, guard stabilizer, video camera, computer, VCR, etc. The direct
video signal from any video component can be fed into the V-1880 and
converted to a usable RF signal that can go to your TV antenna terminals.
Video Fader Used to produce professional fade ins and fade outs.

BP VIDEO GUARD STABILIZER

MODEL

V-1875 m

OUR PRICE $ 45.00 each

Has self contained A&B and bypass switch. Many
movies, concerts and special programs for sale or
rental are copy guarded. This removes copy guard
and allows you to make copies. Many TV sets will
not play prerecorded tapes because copy guard
causes picture to roll and jitter, turn to snow or
disappear. Video Guard Stabilizer removes copy
guard from signal.

BP VIDEO GUARD STABILIZER/
RF CONVERTER

MODEL
V-1877

OUR PRICE $ 69.95 each

Same as above but with a built-in RF Converter
that gives the model V-1877 an RF output which
can be fed directly to the antenna terminals of a
TV set. This enables you to remove the copy guard
from a pre-recorded tape and view it on a TV using
only a VCR..

Use as an RF Converter only. Used in conjunc-
tion with your TV, you can feed direct audio and
video signals from any video device such as video
camera, computer, portable VCR, etc.

BP VIDEO COMMAND CENTER

MODEL V-4803 d>EQ QC

OUR PRICE each

A switcher that can
accept 6 inputs and
direct them to 3 out-
puts. Utilizes switch
similar to one used on
home VCR’s. You avoid
signal loss incurred by
using splitters.

JERROLD 60 CHANNEL
CORDLESS TV CONVERTER

MODEL DRX-3-105

CALL FOR PRICES

• Receive up to 60 TV channels • Remote TV
Control • Attach to any age or model TV in
minutes. • No tools required. • On/Off button.

• 'Channel selection. • Channel Stepping. • Fine
Tuning.

JERROLD JRX TV REMOTE
CONVERTER

MODEL JRX-3C105 (SWITCH)

OUR PRICE $ 79.95 each

Consists of two units
- a receiver and
transmitter. 20 ft con-
necting cord is detach-
able at one end to
help you position the
unit. May be attached to
any age or model TV in
minutes. No tools required.

• Receive up to 36 channels. • Remote
TV control.

BP VIDEO CONTROL CENTER

MODEL V-4802 OC

OUR PRICE ?) ly.yO each

Provides remote con-
trol access of all
Video, TV or Cable,
inputs to TV or Big
Screen TV from one
location by flipping
switch.

• One output, your
TV set or Big Screen TV

• Four inputs • Completely passive, i.e. no AC
power required to operate • Auxiliary input and
output provides added flexibility.

BP UHF CONVERTER FOR TV
AND VTR

MODEL V-5736 Art - Q| -

OUR PRICE each

5 FOR $ 100.00

Use your VCR to its
maximum capability.

Record VHF, UHF,

Cable or Pay TV while
watching any other
mode.

FEATURES • 36 channels

• Allows complete programming
of VTR • Supercolor quality

• Watch or record any combination

of selectable channels. • Receives midband,
superband/Pay and all VHF channels on UHF.

• For Beta/VHS type recorders or TV set • Record
and use TV’s remote control.

BP IMAGE ENHANCER

MODEL V-1 860

Dramatically improves .

performance . - * ' v' '

of video
cameras
and VCR’s.

(off-the-air
or second
generation
recordings),
by compensa-
ting for deteriora-
tion of detail and
sharpness. Includes video distribution amplifier
with two video outputs, allowing you to make two
copies at once without loss in signal level.

BP RF CONVERTER/MODULATOR

MODEL V-1 885

OUR PRICE $ 39.95 each

Allows your TV
to receive video
and audio signals
from image en-
hancer, guard
stabilizer, video
camera, computer, VCR,

The outputs of many video
components cannot be directly hooked up to the
VHF antenna terminals on your TV set. This
problem is solved by using the Model V-1 885 RF
Converter. Converts video signal from any video
component to adjustable RF signal at antenna
terminals. Allows your VCR output to feed two TV
sets at the same time, with virtually no signal loss.

OUR PRICE

$ 59-95 each

Master Charge
VISA ■ COD
Money Order
Check

N.Y. State I
residents add
appropriate I
sales tax.

260 Motor Parkway, Hauppauge, N.Y. 11788

COD’S extra (required 25% deposit)

ADD FOR SHIPPING AND INSURANCE!

$250.00 $4.50

$251 .00 to 500.00 6.50

501 .00 to 750.00 8.50

751 .00 to 1000.00 12.50

over 1000.00 15.00

JjjH (800) 645-9518

in N.Y. State call 800-832-1446

JULY 1983

RADIO-ELECTRONICS

Only NRI Gives You This Kind of Training

and Equipment

Only NRI Gives you So Much Professional
Preparation For a TV/fludio/Video

Servicing Career.

Build this 25" Heath/Zenith Color TV with 112
channel tuning system, infrared remote control,
advanced sound system, and in-set space phone.

Learn how to diagnose prob-
lems using a professional
3 Ms-digit digital multimeter.
Exclusive NRI Action Audio in-
structions talk you through its
complete operation and use.

Learn servicing and
adjustment tech-
niques with this
6-hour, remote con-
trol videocassette
recorder you get as
part of your training.

Perform challenging state-of-
the-art electronic experiments
and demonstrations using your
NRI Discovery Lab®.

See servicing techniques demon-
strated in close-up detail. Graphic
presentations make theory and sys-
tems come alive on NRI Action Vid-
eotapes covering VCRs, disc players,
and TVs.

Get complete, thorough instruction
in the theory, servicing, and repair of
TV, VCR, video disc players, audio
equipment, AM/FM receivers, an-
tenna systems, home video cameras,
projection TV,
and more with
65 easy-to-
digest, bite-
size lessons.

Only NRI gives you so much prac-
tical training with equipment you
learn on and keep. You learn by do-
ing. That’s the way to make it inter-
esting, that’s the way to make it
enjoyable, that’s the way to get the
hands-on experience and know-how
you need.

Hands-On Training For
Real Bench Experience
and Priceless
Confidence

You start with experiments and
demonstrations on the unique NRI
Discovery Lab. You learn basic cir-
cuit wiring and soldering tech-
niques, and then quickly move on to
more advanced concepts as you come
to understand electronic theory,
solid-state devices, digital systems,
and microprocessors. You learn by
actually building and observing the
action of circuitry you’ll be working
with in real-life situations.

Exclusive NRI Training
On Videotape

In addition to profusely illustrated
lessons, you get NRI’s Action Audio
cassette to "talk” you through the
use and operation of the professional
digital multimeter you receive as
part of your equipment. Even more
exciting are your NRI Action Video-
cassettes . . . videotaped lessons that
show you graphic presentations of
electronic systems, vivid closeups of
servicing techniques and profes-
sional "shortcuts” to study and
replay as often as you want.

YOU cet TV, VCR,
DMM and More
Equipment
TO Keep

You also build your own
25" Heath/Zenith color
TV, a state-of-the-art unit
that includes infrared
remote control, a Time Control Pro-
grammer, and the incredible Ad-
vanced Space Phone that lets you
telephone from your chair. Using the
videocassette recorder that’s in-
cluded as part of your training, you
learn how to adjust, service and re-

NRI is the oldest,
largest, and most
successful school
of its kind in
the world. It has pioneered and re-
fined the teaching techniques that
make learning at home the NRI way

7 Decades of
Teaching
Electronics
Skills
At Home

pair these fast-selling units. Your
front-loading VCR features up to
6-hour recording capacity, remote
control, and programmable touch-
button tuning.

The digital multimeter you re-
ceive is a truly professional instru-
ment. You use it in the experiments
throughout your course and as a key
servicing tool on the job. Using the
meter along with the NRI Discovery
Lab, you’ll learn how to measure
voltage, current and resistance and
how to diagnose all types of servic-
ing problems.

Advanced
Systems
Demand
Advanced
Technicians
for Service
and Maintenance

The art of TV/Audio/Video servic-
ing has taken quantum leaps into
the future. Now, successful techni-
cians must understand advanced
concepts like digital control, elec-
tronic tuning, laser video discs,
microprocessors, and more. NRI
gives you the training you need for
success . . . state-of-the-art concepts
and practical, hands-on experience
working with the kind of
equipment you’ll en-
counter on the job.

one of the most economical and effec-
tive methods ever conceived. You
learn at your convenience as a class
of one, backed by skilled NRI in-
structors and carefully designed les-
sons that take you a step at a time
toward your goal. No time away
from your job, no night school grind,
no classroom pressures. Yet your
training is thorough and complete,
with a foundation of hands-on ex-
perience unequalled by any other
training organization.

Send For Free
Catalog
Covering 12
Electronics
Courses

Our 104-page catalog gives you all
the details. In it, you’ll find a sum-
mary description of every lesson,
and photos and specifications for
every item of equipment included in
your course. You’ll also learn about
other fascinating career opportuni-
ties in the world of electronics . . .
Microcomputers, Industrial Elec-
tronics including robotics, Commu-
nications, and more.

Mail the postage-paid card today
for your free copy. See how com-
pletely and how thoroughly NRI gets
you started on your
tomorrow
today.

NRI SCHOOL OF
ELECTRONICS
r McGraw-Hill Continuing
Wj rj JU Education Center
i • PT 3939 Wisconsin Avenue
" H I B Washington, DC 20016

JULY 1983

RADIO-ELECTRONICS

LETTERS

Address your comments to: Letters, Radio-Electronics,
200 Park Avenue South, New York, NY 10003

PRIVACY IN COMMUNICATIONS

Recently, I picked up a copy of Radio-
Electronics quite by chance, and was so
impressed that I subscribed the next day.
Keep up the great work.

I would like to comment on the article,
“Ensuring Privacy in Communications” in the
“Communications Corner” department for
January 1983. The writer seems to be con-
veying a false impression — a mis-
understanding that even many amateur radio
operators have: that by adding a sub-audible
or dual tone signal to your transmission you
can ensure privacy from the casual listener.

Tone-squelch systems do not prevent peo-
ple with scanners from hearing what you say.
The tone squelch simply keeps other radios
(in a fleet, for example) that have a squelch-
muting circuit from being bothered by any
except properly encoded signals. A radio
without that mute circuitry will pick up every-

thing transmitted over a given frequency,
whether or not the transmission has a tone
added to it. Since scanners, and the majority
of monitoring radios, are not equipped with
muting, the tone in no way protects the priva-
cy of the communication. Even radios with
such muting circuits are usually taken off
mute when the microphone is picked up, ena-
bling a listener to hear all the transmissions.
DAN PETERSON
Hemet, CA

ANTIQUE RADIOS

I enjoyed reading Mr. Richard Fitch’s re-
cent article about restoring antique radios
(Radio-Electronics, March 1983). Having
repaired many pre-war radios, and some ear-
ly TV sets, I know the feeling of accomplish-
ment that results from getting one of those
treasures playing again.

I’d like to offer a hint that might make

troubleshooting an old chassis a bit easier.

When smaller tube-radios became avail-
able (and later, when television appeared on
the scene), many an old model was retired
while still in good working order. But alas, 40
years later, when the old unit is dusted off and
plugged in, all that issues from the speaker is
a thin, garbled audio strongly overriden by a
loud AC hum.

Here’s the problem in almost every case
that I’ve come across: The electrolytic capa-
citor in the power-supply circuit has dried out.
Unlike the paper/foil and mica capacitors in
the set, the electrolytics do not have an unlim-
ited shelf life. The liquid electrolytic can
evaporate away, leaving the caps virtually
ineffective.

Two things result: First, the filtering of the
pulsating DC from the vacuum-tube rectifier
becomes very poor. All that’s left to provide a
modicum of filtering is the field coil on the

GETTHE SAME VIDEO TRAINING
THE PEOPLE AT SONY GET

Now you can be trained by Sony even if you
aren’t employed by Sony.

Because we’re making our vast library of train-
ing videotapes available to you. The very tapes that
teach our own engineering, service and sales personnel
The tapes cover the products and concepts of
video and its related technologies. You can learn the
basics of video recording. Color systems.

Digital video and electronics. Television
production. And more.

Plus you can learn how to service
cameras,VTR’s, and other video products.

As professionally as Sony does.

The tapes are pro
duced entirely by
Sony and contain
up-to-the-minute
information. They
communicate clear-
ly and simply And
some of them are
even programmed for
interactive learning.

And learning through video can be done at
your own pace, in the convenience of your home,
shop or school. Reviewing is quick and easy. And
the tapes are always available for reference.

Send for your catalog, which lists more than
250 titles. In your choice of 3/4" or 1/2" formats.

Write Sony Video Products Com-
pany, Tape Production Services,

700 W. Artesia Boulevard,
Compton, California 90220.

Or call (213) 537-4300.

Of course, there’s no
obligation. Except the
obligation you have to
yourself: to find out
about the best train-
ing available in
one of the country’s
fastest-growing,
most lucrative fields.

SONY

Video Communications

Sony is a reg. trademark of Sony Corp.

CIRCLE 28 ON FREE INFORMATION CARD

wabash

diskettes l
$1 .29 each!

Now get Wabash Quality at a CE Price

For over 1 7 years, Wabash has been making high quality
and dependable computer products. Wabash diskettes
are made to provide error-free performance on your com-
puter system because every diskette has been totally and
hypercritically tested. Since you can now buy Wabash
computer products directly from CE, the world’s largest
distributor of magnetic media, you can now get maximum
savings on every order. You can even order toll-free.

New Wabash Six Year Warranty

The quality of Wabash diskettes is stressed throughout
the entire manufacturing process. After coating, all Wabash
diskettes go through a unique burnishing process that
gives each diskette a mirror-smooth appearance. Wabash
then carefully applies a lubricant that is specially form-
ulated to increase diskette life. Then, to keep out foreign
particles, a unique heat seal bonds the jacket and liner
together to help prevent contamination. After 1 00% hyper-
critical testing and certification, Wabash then packages
each diskette, (except bulk pack) in a super strong and
tear resistant Tyvek® evelope. The final Wabash prod uct is
then shrink-wrapped to insure cleanliness and reduce
contamination during shipment. Wabash diskettes are so
very reliable that Wabash now offers a six year warranty in
case of defects in materials or workmanship on all diskettes
purchased directly from Communications Electronics.

New.. .Wabash Diskette Duplication Services

Communications Electronics has teamed up with Wabash to
provide a single-source solution for the diskette duplication
requirements of software developers, OEM’s and distributors.
All service is in-house, to give you fast, dependable service. In
most cases, delivery can be completed in five days. Whether
you require 100, 1,000, or 10,000 copies per week, call CE
first for a no obligation price quote. For additional information,
please write us on your letterhead with your requirements.

SAVE ON WABASH DISKETTES

Product Description

Part#

CE quant.
100 price
per disk ($)

8" SSSD IBM Compatible (128 B/S, 26 Sectors)

Fill

1.89

8" SSSD Shugart Compatible, 32 Hard Sector

F31 A

1.89

8" SSDD IBM Compatible (128 B/S, 26 Sectors)

FI 31

2.39

8" DSDD Soft Sector (Unformatted)

F14A

2.99

8" DSDD Soft Sector (256 B/S, 26 Sectors)

FI 44

2.99

8" DSDD Soft Sector (51 2 B/S, 15 Sectors)

FI 45

2.99

8" DSDD Soft Sector (1024 B/S, 8 Sectors)

FI 47

2.99

5V4" SSSD Soft Sector w/Hub Ring

Mil A

1.49

5V4" Same as above, but bulk pack w/o envelope

M11AB

1.29

5V4" SSSD 10 Hard Sector w/Hub Ring

M41 A

1.49

5V4" SSSD 16 Hard Sector w/Hub Ring

M51 A

1.49

5 V 4 " SSDD Soft Sector w/Hub Ring

M13A

1.79

5V4" Same as above, but bulk pack w/o envelope

M13AB

1.59

5V4" SSDD 10 Hard Sector w/Hub Ring

M43A

1.79

5V4" SSDD 16 Hard Sector w/Hub Ring

M53A

1.79

5V4" DSDD Soft Sector w/Hub Ring

M14A

2.69

5V4" Same as above, but bulk pack w/o envelope

M14AB

2.49

5V4" DSDD 10 Hard Sector w/Hub Ring

M44A

2.69

51/4" DSDD 16 Hard Sector w/Hub Ring

M54A

2.69

5V4" SSQD Soft Sector w/Hub Ring (96 TPI)

M15A

2.59

5V4'' DSQD Soft Sector w/Hub Ring (96 TPI)

M16A

3.69

5V4" Tyvek Diskette Envelopes - Price per 1 00 Pack

TE5

12.00

SSSD = Single Sided Single Density; SSDD = Single Sided Double Density;
DSDD = Double Sided Double Density; SSQD = Single Sided Quad Density;
DSQD = Double Sided Quad Density; TPI = Tracks per inch.

Quantity Discounts Available

Wabash diskettes are packed 1 0
disks to a carton and 1 0 cartons
to a case. The economy bulk
pack is packaged 1 00 disks to a
case without envelopes or labels.

Please order only in increments
of 100 units for quantity 100
pricing. With the exception of
bulk pack we are also willing to
accommodate your smaller or-
ders. Quantities less than 100
units are available in increments
of 10 units at a 20% surcharge
above our 1 00 unit price. Quan-
tity discounts are also available.

Order 500 or more disks at the same time and deduct 1 %; 1 ,000 or
more saves you 2%; 2,000 or more saves 3%; 5,000 or more saves
4%; 1 0,000 or more saves 5%; 25,000 or more saves 6%; 50,000
or more saves 7%, 1 00,000 or more saves 8%, 500,000 or more
saves 9% and 1 ,000,000 or more disks earns you a 1 0% discount
off our super low quantity 1 00 price. Almost all Wabash diskettes
are immediately available from CE. Our efficient warehouse
facilities are equipped to help us get you the quality product you
need, when you need it. If you need further assistance to find the
flexible disk that’s right for you, call the Wabash compatibility
hotline. Dial toll-free 800-323-9868 and askfor your compatibility
representative. In Illinois or outside the U.S. dial 31 2-593-6363
between 9 AM to 4 PM Central time.

Buy Wabash Diskettes with Confidence

To get the fastest delivery from CE of your Wabash computer
products, we recommend you phone your order directly to our
Computer Products Division and charge it to your credit card. Be
sure to calculate your price using the CE prices in this ad. Written
purchase orders are accepted from approved government agen-
cies and most well rated firms at a 30% surcharge for net 30
billing. For maximum savings, your order should be prepaid. All
sales are subject to availability, acceptance and verification. All
sales are final. All prices are in U.S. dollars. Prices, terms and
specifications are subject to change without notice. Out of stock
items will be be placed on backorder automatically unless CE is
instructed differently. Minimum prepaid order is $50.00. Mini-
mum purchase order $200.00. All shipments are F.O.B. Ann Arbor,
Michigan U.S.A. No COD’s please. Non-certified and foreign
checks require bank clearance.

For shipping charges add $8.00 per case or partial
case of 100 8-inch flexible disks or $6.00 per case or
partial case of 100 5y4-inch mini-diskettes for U.P.S.
ground shipping and handling in the continental U.S.A.

Mail orders to: Communications Electronics, Box 1002,
Ann Arbor, Michigan 48106 U.S.A. If you have a Visa
or MasterCard, you may call and place a credit card order.
Order toll-free in the U.S. Dial 800-521-441 4. In Canada,
order toll-free by calling 800-265-4828. If you are outside
the U.S. or in Michigan dial 31 3-994-4444. Telex anytime
810-223-2422. Order your Wabash diskettes today.

OrderToll-Free! wabash

800-521-4414 error-free

In Michigan 313-994-4444 CIISKGltGS

COMMUNICATIONS

ELECTRONICS"

Computer Products Division

818 Phoenix □ Box 1002 □ Ann Arbor, Michigan 48106 U.S.A.

Order TOLL-FREE 800-521 -441 4 or outside U.S.A. 313-994-4444

CIRCLE 81 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

Model V-209

fijWter SX 5VM

Model v 3s ,_ s with

master charge’

CUTS PRICES ON
HITACHI SCOPES

MINI- PORTABLE

dual trace

3 ^ah/rackage 3 * ' H ighsensltivC'
T^' 9 v%fv aX Hzand fast sweep

► Auto-focus • Comes with p

^odes CM ChTR li,ier • D/snf V

\qO MHz DUALTRACE
DELAYED SWEEP

TBACE°DE^viDSWEEP

Model V-650F

High sensitivity • 1 . mV/< 5 L ( 1 c ° h a n H n ei
. 5 ns/div sweep rate • ^ LE, e ann
diqnlav (triqger view) • Variable
?r aae^old off . Full TV triggering
• Single sweep • Automatic focus
correction . Com es with probes^

Model V-1050F

Large, bright 8 ^.^cMjSh 2 , A

^rteo V . Comes wi th probes_

.om

$80 Value

CALL FOR SPECIAL INTRODUCTORY PRICES
TOLL FREE (800) 645-9518 „ N .v. state soo^e

FOROHAM

260 Motor Parkway, Hauppauge, N.Y. 11788

• Master Charge

• VISA

• COD

• Money Order

• Check

electrodynamic speaker (which does double-
duty as a choke in most of the old circuits).
That isn’t enough to prevent a loud hum in the
speaker. Second, there’s usually an
electrolytic capacitor used to bypass the
cathode resistor in the audio-output stage.
When that goes, the AC gain of the stage is
reduced to a fraction of its former level.

Solution? Replace all the old electrolytics.
The values are almost always marked clear-
ly, and modern equivalents are readily avail-
able. Some early electrolytics are rectangular
in shape, like a matchbox covered with wax;
others are enclosed in metal cans attached to
the chassis, so keep that in mind when hunt-
ing for them in your old set. When replacing,
just be sure to use capacitors of equal or
higher voltage, and watch out for polarity. The
exact capacitance value is usually not critical,
and deviations of 25 or even 50 percent will
often work satisfactorily.

So if you have an old set with those
symptoms, try my suggestions first; they may
save you a lot of time and trouble.

DAVID B. WARD
Madison, NJ

ON NIKOLA TESLA

I would like to thank you for publishing my
letter to the Editor in your November 1982
issue of Radio-Electronics. I believe that we
owed that tribute to Nikola Tesla for his many
accomplishments and few rewards. I am also
sure that your readers have appreciated it. It
is a great credit to your magazine to be so
responsive to your readers.

May I now point to a slight discrepancy
between my letter and the published version,
which, I am afraid, may cause confusion
among the experts. My letter said: “Of
course, the General Electric Company, which
originally followed Edison and the DC
approach, abandoned it later and followed
Tesla’s AC direction to grow into the giant of
today.” The published version read: “That
company had followed Edison and the DC
approach, at first; later, it turned to follow
Tesla’s AC direction.”

The substitution of “that company” for “the
General Electric Company” unfortunately
changes the meaning completely, since from
the context, “that company” refers to
Westinghouse Electric.

I would appreciate it very much if you will
once again spare me some of your valuable
space and publish my correction.

Once again, my thanks for publishing the
tribute to Nikola Tesla, the inventor ex-
traordinaire.

SLOBODAN CUK, PH.D.

Assistant Professor of Engineering,
California Institute of Technology

Our apologies for the transcription error
through which the proper antecedent to the
phrase “that company’” was omitted. Editor

VIDEO TRANSMISSION

Just a note on the letter that appeared in
the January 1983 Radio-Electronics by Mr.
Peter K. Onnigan about video transmission
via FM radio stations.

By his statements and incomplete reason-
ing, Mr. Onnigan would have us believe that
high-resolution video can’t be transmitted
over 10-kHz telephone lines or via 3-kHz
bandwidth radio-communications links. Well,
maybe not moving pictures, but ...

RONALD S. MOODY

Bremen, GA R-E

Not ]ust Another Pretty Breadboard

“ « *4^®

> * /

exmx?*

©I#!

MAX-50'

C 1

Ami,

■I

' !

S o you thought Global

Specialties wasy'usfthe lead-
ing manufacturer of Solderless
Breadboarding Systems? Look
again. Over the past 10 years
Global’s developed more than 40
bench-crafted quality test and
design instruments . . .Just for you.

Take your pick. . .We offer
Capacitance Meters, benchtop
and portable, and an array of
complementary instruments to
meet your specific needs. We’ve
got 8 Frequency Counters to
choose from, starting with our
inexpensive MAX-50 and
MAX-1 00 and capped with our
recently-introduced 6002, 1 GHz
model. Our Universal
Counter-Timerfamily includes the
new, widely-acclaimed, handheld
5000 Counter-Timer.

We also make logic probes
and pulsers with frequency and
pulse width ranges to suit any

application or budget. Global's
popular Function and Pulse
Generators are designed with the
same quality as our NBS-certified
Frequency Standard. And a broad
range of accessories, hardware
and cases round out the Global
product line.

Of course, we still manu-
facture the largest selection of
Breadboards and prototyping
equipment anywhere . . .Simple
OuickTest elements with our
patented interlocking system . . .
Experimentor Modules which
combine sockets and bus strips in
popular arrays . . .prototyping
systems which provide
uncomplicated translation from
design to finished product . . .
Mounted solderless assemblies,
including Global's PB-105
Superboard, 50% larger than any
other, and our powered
proto-boards offering a wide

selection of power options.

You depend on us for the best
in breadboards . . . Depend on us
fofthe best in test and design
instruments. Your pocket won’t
take a beating either. Global
provides the specifications and
features you require now. . .at
prices you can afford today.

Remember. . . We’re not just
another pretty breadboard. If you
need something for Test or
Design, we’ve probably got it. So
give us a call Toll-Free . . .TODAY.

Ginvi

GLOBAL SPECIALTIES
CORPORATION

70 Fulton Terr., New Haven, CT 06509
(203) 624-3103 TWX 710-465-1227

OTHER OFFICES:

San Francisco (415) 648-0611, TWX 910-372-7992,
Europe: Phone Saffron-Walder 0799-21682,

TLX 851-817477

Call toll free for details 1 -800-243-6077 during business hours

CIRCLE 31 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

EQUIPMENT REPORTS

Philips Model PM 3215
50-MHz Dual-Trace
Oscilloscope

Philips

OVERALL

PRICE

INSTRUCTION

MANUAL

PRICE

CIRCLE 103 ON FREE INFORMATION CARD

YOU CANNOT BE INVOLVED WITH

electronics — by profession or even as a
hobbyist — without eventually needing an

oscilloscope. And today’s advancing
technology often demands an oscillo-
scope with a wide bandwidth. If you have

found that to be true in your experience,
and if you are contemplating an oscillo-
scope purchase, one unit you should not
overlook is the PM 3215 from Philips
Test and Measuring Instruments, Inc. (85
McKee Drive, Mahwah, NJ 07430).

General overview

The PM 3215 is a dual-channel scope .
with a 50-MHz bandwidth. It is relatively
lightweight (less than 18 pounds) and
measures 17.5 X 11.8 x 5.4 inches.
(Those measurements do not include the
front protective cover, the controls, or the
handle.) The handle, with its nine locking
positions, doubles as a stand for the
scope.

The inclusion of a battery input (22-27
volts DC at 1.1 amp maximum) along
continued on page 28

New Simpson Test instruments for the 80's

FAST PROFITABLE BENCH OR FIELD SERVICING

Order Them from
Your Local
Electrical/
Electronics
Distributor

SIMPSON ELECTRIC COMPANY

A Katy Industries, Inc. Subsidiary
853 Dundee Avenue, Elgin, IL 60120
] (312) 697-2260 • Cable SIMELC0 • Telex 72-2416

DIGITAL MULTIMETER

Deluxe Test Lead Kit s 57 165 Handi-VOM $ 78

Three new DMMs offer high accuracy,
beeper, diode test, transient protection
and double fusing.

The 470jm is our new low-cost full-func-
tion hand-held (calculator style) DMM with

25 ranges.

The 467E hand portable DMM
has peak hold, true RMS and

26 ranges.

The 360 Series 3 digital VOM (with
world famous 260® styling) has 28
ranges, bright LED display, recharge-
able batteries.

Our Model 165 Handi-VOM is a pocket-
size unit with 22 ranges includ-
ing dB, large 3 Va " meter, convene
ient one-knob selector switch.

The Deluxe Test Lead Kit (Catalog No.
00818) has everything you need for fast,
convenient test setups, measurements
and trouble-shooting.

360 Series 3 s 275

CIRCLE 91 ON FREE INFORMATION CARD

PHOTOVOLTAIC

PROJECTS

i? m&mm
nmm% c mm
! >.•« iisie :

KM WEEKEND
ELECTRONICS
PROJECTS

Hundreds of time- and

THE COMS Mm Of

VIDEOCft66CTTe

ffiscom>cfi6

&*0 SOttfOS

EXPLORING
ELECTRICITY
AND ELECTRONICS
WITH PROJECTS

ar .joms £»w*«»s

1406

List $17.95

1467

List $16.95

; VIDEO I W
j ELECTRONICS !
ITECHNOiDOY 1

ELECTRIC
MOTORS &
CONTROL
TECHNIQUES

OIGITRL

fiUDO

CHNQLQi

urn TO

OESm 80110 &
PB06RAM YOUR OWN
mmm working

COMPUTER SYSTEM

SI fcLcUTIiuHlC
POWER SUPPLY
PROJECTS

rr*i r— n

' money-saving ideas for
hobbyists, experimenters '' H
and technicians! fe

Select 6 fact-filled volumes

for only $095 (total value up to $115.70)

1505

List $18.95

1296

List $18.95

Tu Electronics Book Club

Blue Ridge Summit, PA 17214

Please accept my membership in Electronics Book Club and
send the 6 volumes circled below, billing me $2.95 plus
shipping and handling charges. If not satisfied, I may return
the books within ten days without obligation and have my
membership cancelled. I agree to purchase 4 or more books
at reduced Club prices (plus shipping/handling) during the
next 12 months, and may resign any time thereafter.

1000

1062

1113

1160

1199

1211

1276

1277

1296

1332

1346

1406

1435

1436

1451

1465

1467

1468

1473

1474

1486

1497

1505

1536

Phone _

Address

City

State Zip

Valid for new members only. (Orders outside U.S. or Canada must be prepaid in
International Money Orders in U.S. dollars. Canada must remit in U.S. dollars.)
This order subject to acceptance by Electronics Book Club. RE-783

VERBAL CONTROL MMP r :

w«« mjr HOW TO

MICROCOMPUTERS FI «|»/|U!tO ^

sr«8£*u<5i5&Y I REMOTE CONTROL I

I OEViCES

1468

List $18.95

1277

List $19.95

1497

List $15.95

1451

List $18.95

1474

List $15.95

1113

List $11.95

1199

List $18.95

1062

List $14.95

1276

List $15.95

1346

List $19.95

COmPUTER

GRAPHICS

iuith.e'T reariy-ta-run

programs & * otara*

1436

List $16.95

1465

List $15.95

1160

List $13.95

1211

List $14.95

c ^ ^

1486

List $17.95

| 7 very good reasons to try j

Electronics Book Club

| Blue Ridge Summit, PA 17214

|§ • Reduced Member Prices. Save 20% to 75% on books sure to

|| increase your know-how ||

§| • Satisfaction Guaranteed. All books returnable within 10

U days without obligation f|

|| • Club News Bulletins. All about current selections— mains, |f

|| alternates, extras— plus bonus offers. Comes 13 times a year |§

gf with dozens of up-to-the-minute titles you can pick from M

|f • “Automatic Order.” Do nothing, and the Main selection
|| will be shipped automatically! But ... if you want an Alter-
H nate Selection— or no books at all— we’ll follow the instruc- ||

H tions you give on the reply form provided with every News
< Bulletin %

|| • Continuing Benefits. Get a Dividend Certificate with every

U book purchased after fulfilling membership obligation, and j|

|§ qualify for discounts on many other volumes
|| • Bonus Specials. Take advantage of sales, events, and it

|f added-value promotions ||

|| • Exceptional Quality. All books are first-rate publisher’s §§

|| editions, filled with useful, up-to-the-minute information

CIRCLE 33 ON FREE INFORMATION CARD

JULY 1983

DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS

AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS

im-

electronic components

AUTHORIZED

DISTRIBUTORS

ALABAMA

Birmingham American Electronic Supply

Birmingham J.L.S. Electronics

Birmingham Long's Electronics

Florence Fuller Distributing

Huntsville Industrial Electronic Supply

Huntsville W&W Electronics

Mobile Forbes Electronics

Montgomery Handey's Electronic Center

Opelika Southern Electronic Corp.

Tuscaloosa Radio Parts Inc.

CONNECTICUT LOUISIANA NEVADA TENNESSEE

Avon Heathklt Electronic Center Baton Rouge Davis Electronic Supply Las Vegas Century 23 Memphis Warren Radio

New Haven Customized Computer Center Baton Rouge Industrial Elect. Supply

Wallingford . .
Westport . .

Newark

New Castle
Wilmington .
Wilmington .
Wilmington .

. . Tron Town USA Baton Rouge Menard Electronics

Murfreesboro Murfreesboro Radio & Elect.

Murfreesboro Standard Auto Parts

Computer Works Gretna.

DELAWARE

n Computerland Lak(J Char |' es

Delaware Amateur Supply Motairjo

Laraco / Lafayette Radio ™ '

Micro Products

Pelican Electronics «•*•* £<Me «a.o„s Pa« Co

Pelican Electronics

. . Heathkit Electronic Center
Wholesale Radio Equipment
Pelican Electronic Supply

ALASKA

Anchorage Electronic Supply Center

Anchorage The Electronic Company

Anchorage Wapatco

ARIZONA

Lake Havasu City Electronics 4-U

Sierra Vista B&S Electronics

Tucson Electronic City

Tucson Heathkit Electronic Center

Yuma Yuma Electronics / LTD Investment Orlando
Orlando

. . Wholesale Electronics

Coral Gables

Clearwater

Fort Lauderdale .

Gainesville

Hialeah

Hollywood

Jacksonville

Miami

Little Rock

Anaheim

Bakersfield

Berkeley

Buena Park

Campbell

Chico

Chula Vista
Chula Vista .
Clearlake
Concord . . .
Corning
Costa Mesa

Covina

Cucamonga

Cypress

Davis

Eureka

Fontana
Fresno
Fresno
Glendale . .
Goleta

ARKANSAS

Southern Electronics

Oakland Park . .
Panama City . .

Pensacola

CALIFORNIA Pensacola

Heathkit Electronic Center Pensacola

R F. Electronics Plantation

Jay Kern Electronics Tampa

Al Lasher's Electronics

Ford Electronics

Heathkit Electronic Center Atlanta

Payless Wholesale Atlanta

Lion Electronics La Grange

. Salto Electronics s,one Mountain

Clearlake Electronics Warner Robbins

Pacific Radio Supply
Nor-Cal Electronics Hilo

Mar-Vac Electronics Honolulu

G&H/AMCO Elect Supply Honolulu

Abletronics p ear | city
S.C.R. Electronics
Paradyme Consumer Elect .

Redwood Electronics Boise

Fontana Electronics Pocatello

Sparky Electronics Twin Fal,s

Whitcomm Electronics

Eagle Electronics Addison

Bill's Stereo Berwyn

. Olson Electronics

Heathkit Electroniclfcenter

Errico Inc.

Heathkit Electronic Center

. Lafayette Stereo Select.

Lafayette Radio
Bay-Mar Electronics

Forbes Electronics

: Grice Electronics

Quad Electronics

. Heathkit Electronic Center
. Heathkit Electronic Center

Shreveport
Shreveport
Shreveport . .

Fairlawn
Mantua . .
Ocean .
Somerset , ,

,.Wm, B. Allen Supply Co. '

Electronic Supply of Shreveport v,mMana
Industrial Electronic Supply
Southern Electronics Alamagordo

MARYLAND

Heathkit Electronic Center Nashvj|le Electra Dist Co

Electronic World 0ak Rldge Mr . Radio

Heathkit Electronic Center 0 ak Ridge National Electronics

Radl0s Unlimited Smyrna De)ker E | ectronjcs

Lafayette Radio Supply Tuii a fioma H & H Electronics

Laraco/ Vineland

TEXAS

NEW MEXICO

Basin Electronics

NORTH CAROLINA

Brownsville George's Electronic Mart

Dallas Heathkit Electronic Center

Enid Trice Electronics

Aberdeen. .... —

Harco Electronics

Greensboro

Heathkit Electronic Center

Fort Worth

Heathkit Electronic Center

Annapolis

Baltimore

Computers Etc

Heathkit Electronic Center

Winston-Salem

Trayer-Yelverton Inc.

Garland

Harligen ...

Tinker Tronics

George's Electronic Mart

Beltsville

Mark Electronics

NEW YORK

Houston

Heathkit Electronic Center

College Park .

..Electronics Plus

Albany ....

Greylock Electronics

Lubbock

Trice Electronics

Damascus. . .

Damascus C.B.

Amherst 1 .
Buffalo .

Heathkit Electronic Center

McAllen

Carlos Franco Electronics

Glen Burnfe

. . . : . -...' . Revacto of Maryland

Olson Electronics

McAllen

George's Electronic Mart

Laurel

The Comm Center

Buffalo . . .

Radio Equipment Corp.

Richardson . . .

Martin Wholesale Electronics

Lavale . .

. J & M Electronics

Commack .

Spartan Electronics

Richardson

Trice Electronics

Rockville

Heathkit Electronic Center

Hornell

Hornell Electronics

San Antonio . .

C&K Electronics

Rockville

.Revacto of Maryland

. . Futronicslnc.

Ithaca

Rad-Tronics

San Antonio . . .

Heathkit Electronic Center

Severna Park : .

Jamestown . . .

Warren Radio

Waco

L&M Wholesale

Danvers
Littleton i;
Peabody .

Half Moon Bay Strawflower Elect. /Radio Shack carbondale

Chicago

Decatur

Downers Grove .

Groveland

Harvey

Melrose Park .
Mount Prospect

Niles

Peoria

Rockford

Rock Island

Skokie

South Holland

Harbor City Bluff Electronics

Hawaiian Gardens Carson Electronics

Hollywood Pacific Radio Exchange

Inglewood Radioland / Inglewood Elect.

La Habra A.B.C. Electronics

La Mesa Heathkit Electronic Center

Lancaster Consumer Electronics

Los Angeles Heathkit Electronic Center

Modesto Inland Electronics

Modesto Pacific Radio

Monterey Zackit

Morro Bay Coast Electronics

National City Willy's Electronics

Oakland Cass Electronics

Oceanside Electronic Center

Oroville Radio Mart

Palo Alto U S. Electronics

Palo Alto Zack Electronics

Pasadena Dow Radio

Paso Robles Mission Electronics

Pomona Heathkit Electronic Center Angola

Redding Radio Mart Bedford . . .

Sacramento Cal Radio & TV Bloomington

Sacramento Zackit Chesterton .

Salinas Salinas Radio Evansville .

San Bruno Bruce Electronics Gary

San Carlos J&H Outlet Indianapolis

San Diego Radio Shack /Mira Mesa Indianapolis.

San Fernando San Fernando Electronics Lafayette . .

San Francisco Zack Electronics Muncie —

San Jose Peninsula Elect Supply South Bend

San Jose United Radio and TV South Bend

San Luis Obispo Mid State Electronics Terre Haute

San Rafael Electronics Plus

Santa Clara Digital Pacific

Santa Cruz Santa Cruz Electronics

Santa Fe Springs Industrial Electronics

Santa Maria Caps Communications

Santa Maria Electronic Parts Supermart n a " P nnnrt

South Lake Tahoe Calpine Electronics p

Sunnyvale Sunnyvale Electronics

Torrance Signal Electronics

Torrance Torrance Electronics

Tracy G-TEC

Tustin A B C. Electronic Supply

Vallejo Zackit

Van Nuys Thrifty Electronics

Westminster JK Electronics

Whittier

Woodland Hills

Yuba City Electronic World

GEORGIA

A.C.M. Computer Mart

. . Heathkit Electronic Center

Coleman sE ec romcs Waltham
...C&L Electronics Wallesley

HAWAII f|

At's Electronics Ad jan

. .industrial Electronics ... p rb '
integrated Circuit Supply ™ '

Heathkit Electronic Center BaUleCr8ek
IDAHO Bay City . .

7f .'Kimball Electronics Canton

Kimball Electronics Dearborn. |

. Central Electronics Detroit .

Detroit

ILLINOIS Detroit

. Digital World. Inc. East Detroit

B B.&W. Electronics F enton

.Pick’s Electronics . Flint '

Heathkit Electronic Center Grand Haven

Howard Electronic Sales Grand Rapids .

. Olson Electronics Grand Rapids

University of Illinois Bookstore G rand Rapids

Main Street Computer Grand Rapids

Heathkit Electronic Center Holland

Moyer Electronics Jackson

George Electronics Kalamazoo. ..

Olson Electronics Lansing

Tri- State Electronic Corp. Lansing

.Computerland of Niles Uvoniai

Joseph Electronic Madison Heights

- Computerland Madison Heights

Warren Radio Co Midland

Computer Store of Rockford Mount Clemens

Team Electronics Muskegon'

Lillipute Computer Niles

Union Electronic Dist 0wOSSO '

INDIANA Port Huron .

Lakeland Electronics Saginaw

. Etex Mart Saint Clair Shores . .

Sterlinn HBinhfc

Suiteiand Suburban Wholesalers Jericho

Towson . BaynesvtUe Electronics Johnson City

Towson Computers Unlimited Kingston , . ,

m -■ Newburgh .

MASSACHUSETTS New York

. . Computer Electronic Consultants New y ork

• Tel-Comlnc. Poughkeepsie

Heathkit Electronic Center R ens slaer

Pittsfield Radio Equipment Rochester

Computer Mart Inc Seneca

Heathkit Electronic Center Troy

MICHIGAN Utica

...... ., . . . . . . . .E&B Electronics White Pla ) ns

. ; ... .Olson Electronics White Plains

... .Wedemeyer Elect. Supply

..Warren Radio Fargo

Kinde Distributing Fargo

. The Electronic Connection

Westside Radio

Electronic Parts Co. Akron

Heathkit Electronic Center Bucyrus

Detroit S&S Electronics Canton

Heathkit Electronic Center Cincinnati . . .
. . Tri-County Electronics Cincinnati

Shand Electronics Cleveland . .

K.S Electronics Columbus

Micro World Inc. : , Columbus .

. .Radio Parts Inc. Dover

.T&W Electronics Lima

. .Warren Radio Massilion ,

.......... . Bits & Bytes Mogadore . ; .

..... Fulton Radio Supply Parma

.Warren Radio Toledo

... Fulton Radio Supply Toledo

Wedemeyer Elect. Supply Youngstown

Norwest Electronics Youngstown .

Olson Electronics

'. . . 'computromx Oklahoma City
...... Olson Electronics

H&R Electronics Albany
Niles Radio Supply Beaverton .

Warren Radio Corvallis

. Mam TV Radio Electric Corvallis

, . Ryder Dist. Portland . .
Bell Electronics Co.

. Heathkit Electronic Center
. Unicorn Electronics
Greylock Electronics

Action Audio Inc.

. Manhattan Electronics
Taft Electronics

UTAH

Midvale Heathkit Electronic Center

Ogden Carter Supply Co.

Provo Alpine Electronic Supply

Salt Lake City Best Distributing

Greylock Electronics Sal ’ Lake Ci, V Kimba " Electronics

Electronic Stockroom Sal > Lake City Mountain Coin Distributing
Salt Lake City RA-ELCO Inc.

. . Heathkit Electronic Center
. .„ Olson Electronics

.Troian Electronic Supply
. Central Electronics

Computer Corner

Heathkit Electronic Center

NORTH DAKOTA

. Radios TV Equipment

S/S Electronics

OHIO

... ... Warren Radio

. Mead Electronics

....;, .... .Electronic Center Inc
. . . . Heathkit Electronic Center

Micro Solutions

. Heathkit Electronic Center

. . .. Heathkit Electronic Center

.Olson Electronics

. &•;. . . .T V. Specialties

...... . ; ....'. Warren Radio

M.H. Martin Co,

: . . .... Olson Electronics

. . . . . . .Superior Electronics

Fjeathkit Electronic Center

VERMONT

Burlington Greylock Electronics

Essex Junction I .E.S. Lafayette Radio

VIRGINIA

Alexandria Heathkit Electronic Center

Annandale Arcade Electronics

Arlington .. Arlington Electronic Wholesalers

Blacksburg Scotty s Radio S TV

Charlottesville Graves Electronics

Falls Church Crossroad Elect. Wholesalers

Hampton Cain Electronic Co. Inc.

Harrisonburg Electrical Wholesalers

Hopewell B&G Electronics

Lynchburg Electronic Service Co.

Norfolk Avec Electronics

Norfolk .... Cain Electronics

Norfolk Priest Electronics

Richmond Avec Electronics

Roanoke Avec Electronics

Vienna Electronic Equipment Bank

Virginia Beach Cain Electronic Co. Inc.

Virginia Beach Heathkit Electronic Center

Woodbridge Virginia Micro Systems

Stansifer Radio Sterling Heights Electronic Supermarket Salem

... _nl T at/lAf CloAtrnnir AA/nrlH

Chesterton Electronics Ta y ,or
Hutch & Son Taylor

Calumet Electronics Traverse City

. Heathkit Electronic Center Westland

. Warren Radio Co
. . .Von’s Electronics Bu | uttl

. Pierce Electronics H opk j ns

Radio Distributing Co. Minneapolis

TV Supply Co. saint Paul. .

. Industrial Electronics yvinona

Ames

Burlington .
Clinton .

Des Moines .
Des Moines

IOWA

Electronic Supply, Inc-.

8i!oxi . c

■ iVu% • , v „ Dickson . .

Union Supply Co. Pascagoula

R.J .S. Electronics
Warren Radio Co.

Gifford Brown Inc Bridgeton . .

Radio T rade Supply Columbia . .

Kansas City

Electronic World •: Salem ....
... Tel Van Electronic Supply

Traverse City Elect Supply p

Olson Electronics Braddock

Butler

MINNESOTA Chambersburg

. . Northwest Radio of Duluth orexelHill
Heathkit Electronic Center Drums
Acme Electronics E r j e
. . Heathkit Electronic Center Fairyiew

Hiawatha Electronics Frazer

MISSISSIPPI McKeesport

. Hooper Electronic Supply Norristown

... Ellington Electronic Supply Philadelphia
... Hooper Electronic Supply phlla delphia
Phoertixviile .

MISSOURI Pittsburgh .

... Heathkit Electronic Center Pittsburgh

Show Me Electronics Pittsburgh

. Burstein & Associates Reading
Electronic Supply Co. Inc. Sweet Valley

Warren Radio

WASHINGTON

Olson Electronics

Bellevue

A B C. Communications

... Ross Radio Co.

Everett

A B C. Communications

OKLAHOMA

Hoquaim . . .

Harbor Electronics

. , . . Trice Wholesale Electronics

Kennewick . .
Kent

C&J Electronic

Electronic Supermart

OREGON

Moses Lake . .

Ron s Electronics

Oregon Ham Sales

Mount Vernon

Cascade Electronics

. . : Norvac Electronics

Olympia

The Electronic Shop

... v Norvac Electronics

Pasco

Radio Shack

. ... The Electronic Super Store

Pullman

H&O Electronics

. Portland Radio Supply

Richland

Radio Shack

. . Roseburg Musical Instrument

Seattle

A.B.C. Communications

: . . . .Computer Specialties

Seattle

Amateur Radio Supply

Norvac Electronics

Seattle

Electronic Supply Co

’ENNSYLVANIA

Seattle

Heathkit Electronic Center

Left Electronics

Spokane

D S C. Sales & Service

Computer Center

Spokane

Personal Computer

, . . Sunrise Electronic Dist.

Tacoma

C&G Electronics

Kass Electronic Dist.

Tukwila

Heathkit Electronic Center

, Mt. D's Digital Electronics
Warren Radio

Vancouver

Heathkit Electronic Center

WEST VIRGINIA

KANSAS KanSaS City

STS:: :£KSSS£ £% '“ k

ar Hea,hki, r“ £8k g-»

MONTANA " ‘

Bell Electronics

Heathkit Electronic Center
Barno Radio
. : The Computer Corner
. Heathkit Electronic Center
. Spectrum Electronics
Stevens TV & Electric
Heathkit Electronic Center

South Hills Electronics

The Computer House
Hamline Electronics
. . Hamline Electronics
G.Y.C. Co.

Elkins

Fairmont

Morgantown

Wiliams Electronics
T P S. Electronics
Computer Corner
Electro Dist . Co.
State Electronics

Wheeling Industronics

WISCONSIN

Kenosha Chester Electronic Supply

Milwaukee Amateur Electronic Supply

Milwaukee . Heathkit Electronic Center

Milwaukee Olson Electronics

COLORADO

Colorado Springs Centennial Electronics

Denver Fistell's Electronics

Denver Fistell's Microelectronics

Denver Mountain Coin Machine

FOREIGN

Marianas Electronics
. Electronica Pan Americana

Sonitel S.A.

TropelcoS.A.

RHODE ISLAND

cun, ww i unow wie tiectronics Jabbour Electronics

y a na • _ Electronics Inc. Pawtucket Jabbour Electronics

Whither Electronics Topeka Carroll Radio & TV Supply MONTANA Providence Hope Electronics

Heathkit Electronic Center Wichita Amateur Radio Equipment Billings, Conley Radio Supply Warwick... Heathkit Electronic Center

Wichita Lloyd's Radio &Elex Bozeman Electronic Services Dist.

Wichita RSClnc. Great Falls Art's Electronics TENNESSEE

Great Falls Electric City Radio Bristol Shield's Electronic Supply

KENTUCKY wfboacka Concord National Electronics

ENTUCKY NEBRASKA Cookeville Wagnon s Stereo Center

ST 'SESSSSk SP m ^ - Computer Systems tnc. Dyersburg Warren Radl0 nio rouidS o,u,«

£ J J v 5 e o . - Heathkit Electronic Center Lincoln Scott Electronic Supply Knoxville Shield's Electronic Supply RioPedras RadioShack

, akPwond n h rnimn x. rn 0 “ Pee r' ess E| ectrontc_Eq^p_ Co. Norfolk Caauwes Gun & Hobby Shop Memphis Bluff City Electronics Singapore Applied Digital Systems

P duca Warren Radio Co. Omaha Heathkit Electronic Center Memphis Memphis Amateur Electronics West Indies: Trinidad The Hobby Centre

For Distributor Information, write or phone JIM-PAK, 1355 Shoreway Road, Belmont, CA 94002 (415) 595-5936

AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS •

Guam: Agana
Guatemala
Panama
Panama
Puerto Rico:

Mayaguez Zitro Electronic & Video Center

Rio Pedras Microcomputer Store

CIRCLE 11 ON FREE INFORMATION CARD

AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED DISTRIBUTORS • AUTHORIZED

• POWER CORDS • BOOKS • STORAGE SYSTEMS • SOLAR PANELS • INTEGRATED CIRCUITS • JOYSTICKS . TRANSFORMERS • BUZZERS • SPEAKERS • FANS • TOOLS • SOLDER • CASES^

“IODES • TRIMMER CAPACITORS • TRANSISTORS • RESISTORS • CONNECTORS • PLUGS • HEAT SINKS • FUSEHOLDERS • TEST CLIPS

QUALITY KITS

liarm/m. ★★★★★★★★★★★★★★★★★★★★★★★★★★

im-Dak $2.00 REBATE!

★ ★★★★★★★★★★★★★★★★★★★★★★★★★

electronic components

Buy one or more of Jim-Pak’s electronic kits and receive a $2.00 factory rebate for each kit you purchase
from one of the authorized Jim-Pak distributors shown on the opposite page. Just remit the coupon below
along with your ORIGINAL sales slip and receive a $2.00 rebate direct from the Jim-Pak factory for each kit
purchased.

5VDC - 1 Amp
REGULATED
POWER
SUPPLY KIT ^

120VAC input, j?
Includes
components,
hardware and
instructions.

JE200

±5 to ±15VDC ADJUSTABLE
REGULATED POWER

SUPPLY KIT

120VAC input.

Output per v;
supply 5VDC
@ 500mA,

10VDC @ 750mA,
12VDC @ 500mA,
15VDC @ 175mA.
LED “On”
indicator.

JE215

DIGITAL THERMOMETER

JE300

Dual sensors - switch controls for in-
door/outdoor or dual monitoring. Extends
to 500'. Range: -40 °F to 199 °F. Calibrate
for Fahrenheit/Celsius. .8" ht. display. AC
adapter included.

6-DIGIT CLOCK KIT (.300" Ht.)

JE701

115VAC - 12 to 24 hour operation. In-
cludes components, case and wall
transformer. Viewable to 20 feet. 6%" x
3% "•

Output: 10VDC to
100mA in series.
5VDC to 200mA in
parallel. Contains
20 solar cells.
Power line taps
select from 0.5VDC
to 10VDC in
0.5VDC in-
crements. Provides
currents for small
battery power
applications.

SOLAR CELL
PANEL KIT

JUMBO 6-DIGIT CLOCK KIT
(.800" Ht.)

115V AC, 12 to
24 hour.
Viewable to 30
feet. Includes
components,
case and wall
transformer.
6%" x 3%".

JE305

JE747

FUNCTION GENERATOR KIT

Three waveforms:
sine, triangle, square.
Range from 1Hz to
100kHz. Output
amplitude from 0 volts
to over 6 volts. Uses a
12V or a ±6V split
supply.

ASCII ENCODED KEYBOARD KIT

JE2206B

JE610

60 Keys generate the 128 characters, up-
per and lower case ASCII set. Fully buf-
fered. Two user-definable keys provided
for customer applications. Caps lock for
upper case only alpha characters. Utilizes
a 2376 (40-pin) encoder read only memory
chip. Outputs directly compatible with
TTUDTL or MOS logic arrays. Parallel
output. Easy interfacing with a 16-pin DIP
or 18-pin edge connector. Interfaces into
most computer systems. Requires + 5V
@ 150mA and -12V @ 10mA. Size: 1 V% "H
x 6V2 "W x 13V4 "L.

• REBATE COUPON • REBATE COUPON • REBATE COUPON • REBATE COUPON • REBATE COUPON • REBATE COUPON •

|t $ Please send my refund for $

|T| for kits. I have enclosed my

ORIGINAL sales slip.

NOT VALID WITHOUT

ORIGINAL SALES RECEIPT.

EXPIRES JULY 31,1983

ONE REBATE PER CUSTOMER

NAME

ADDRESS

CITY

STATE ZIP

PHONE (

Send directly to JIM-PAK, 1355 Shoreway Road, Belmont, California 94002

^PON • REBATE COUPON • REBATE COUPON • REBATE COUPON • REBATE COUPON • REBATE COUPON • REBATE COUPON •

See your local JIM-PAK distributor listed on the opposite page.

KITS • MICROPROCESSOR COMPONENTS • LED’S • SOCKETS • TANTALUM CAPACITORS • AXIAL CAPACITORS • DISC CAPACITORS «

CIRCLE 11 ON FREE INFORMATION CARD

♦ JOYSTICKS* TRANSFORMERS* BUZZERS* SPEAKERS* FANS* TOOLS* SOLDER* CASES* ENCLOSURES* KEYBOARDS* GRAB BAGS » KITS* DIP JUMPERS* CABLE ASSEMBLIES*

RADIO-ELECTRONICS

EQUIPMENT REPORTS

continued from page 24

with its light weight and compactness,
protective panel cover, and handle, in-
dicates that Philips wanted the PM 3215
to be at home either on a laboratory bench
or in the field.

The CRT display has an internal grati-
cule (an 8- X 10-cm grid) with con-
tinuously variable illumination. Those
features reduce parallax error and help to
make reading the scope non-fatiguing,
especially if you use the scope for long
periods of time.

When the scope is first turned on, the
blue trace appears within 10 seconds, and
the unit is ready for immediate use,
although a 30-minute warmup time is
suggested in the manual. The trace comes
on about 4/ 1 0 of a division below where it
was when the unit was turned off.
However, after the 30-minute warmup
period, it has returned to its previous posi-
tion and there is negligible drift in the
trace thereafter.

The unit comes supplied with two pas-
sive probes with an attenuation factor of
10 (and a compensation range from 14 to
40 pF — full probe-compensation in-
structions are included in the manuals). A
handy zero- or ground-check button is
included on the probe shell. The probes

also come with a variety of accessories.
They include a spring-loaded test clip,
extra probe tips, and special caps for the
probe tips that help to make measure-
ments on dual in-line packages or in de-
nsely wired circuits easier. An adapter for
making measurements of wire-wrapped
circuits is also included with the probes.

A look at the controls

The front panel is well organized and
laid out in a neat, compact manner with
the controls appearing where you would
want — and expect — them to be. The con-
trols can be grouped into three main sec-
tions. The first section includes the power
and CRT controls. The second section
contains the vertical-channel controls,
and the third contains the triggering and
horizontal-channel controls. We’ll look
at each section in more detail, starting
with the first, which is located to the right
of the CRT screen.

The illum control acts as the power
switch as well as the continuously vari-
able graticule-illumination control. An
LED immediately above that control in-
dicates power on. Other controls in this
section include those for trace intensity
and focus. A screwdriver-adjustable
trace rotation control is included to
allow you to align the trace with the hori-
zontal graticule lines. Also included in
this section is an output terminal, labeled
cal, which is the source of a 1.2- volt

squarewave having a frequency of about 2
kHz. That can be used for vertical-
channel calibration or when compensat-
ing probes.

The second section includes two col-
umns of controls for the “A” and “B”
vertical channels. They include BNC
input-jacks, above each of which are two
pushbuttons — one grounds the input and
the other selects AC or DC input-
coupling. Above each set of pushbuttons
is a ampl/div which consists of two con-
centric knobs. The outer knob — with 12
click-stop positions from 2 mV/div to 10
V/div in a 1-2-5 sequence — selects the
vertical-channel multiplier. The inner
knob has a click-stop cal position and
can be used to continuously vary the
vertical-channel scale multiplier. A posi-
tion control is located above each ampl/
div knob allows you to vary the vertical
position of the display.

Centered above each of the two col-
umns of controls for the “A” and “B”
vertical channels is a 5-position pushbut-
ton switch that is used to select the
vertical-display mode. Your choices in-
clude looking at signals on channel “A”
only or channel “B” only (positions a
and b respectively), or looking at both
(alt or chop — chosen depending on the
sweep rate that is in use). You can also
look at the sum of the signals at the “A”
and “B” inputs or, by pulling out the
channel-B position control, you can in-

THIS CATALOG IS YOUR KEY TO
INCREASED EFFICIENCY AND
PRODUCTIVITY. AND BECAUSE IT’S
FREE, YOU’VE ALREADY STARTED
TO REDUCE COSTS!

This is our
catalog... The Wire
Handlers. It’s filled
with wire handling
tools designed and
engineered to make
your life easier. The
tools are unique...
unique in design,
and unique in the
way they perform.

You may know
about our Wire
Strippers...but
we also offer the
finest power electric
desoldering tools, termination kits,
wire and cable cutters, slitters, crimpers, and low cost
voltage testers, available. Ask for your copy of The Wire
Handlers today! Just send your business card.

*§ PALADIN

S CORPORATION

Suite 106, 31332 Via Colinas, Westlake Village, CA 91362
Call [213] 991-4970.

• Compact

• Self locking/quick
release

• Easy to carry

• Oil resistant
plastic

• Easy size
identification

• Color coded
yellow-inch
red-metric

HEADACHE
SORTING
HEX KEYS?

Cure it

With Bondhex™
Key Cases!

Cases available with:
Balldriver™ or Chamfered L-Wrenches

WRITE OR PHONE FOR FREE INFORMATION

BONDHUS==^^

CORPORATION —

Box 667

1400 East Broadway
Monticello, MN 55362 U S A.
Tels: 612/295-5500 800/328-6310
TWX 910/578-1094

^£=BONDHUS

Canada Sales Office
190 Highway 7 West Unit #8
Brampton, Ontario L6V 1A1
Tel: 416/453-7470
Telex: 06-97856

CIRCLE 93 ON FREE INFORMATION CARD

CIRCLE 17 ON FREE INFORMATION CARD

The Bearcat® 100.

The first no crystal hand-held scanner.

Now you can have the
one scanner you’ve always
wanted — a no crystal, fully
synthesized hand-held
scanner. The incredible,

Bearcat 100.

Push button programming.

The Bearcat 100 works just like the
full size, no crystal Bearcat Scanners.
Push button controls tune in all police
calls, fire calls, weather warnings,
and emergency information broad-
casts, the split second they happen.
Automatically.

All the features you want.

16 channels for storing
frequencies. 8 band cover-

age-including high, low, UHF and
U T” public service bands; both the 70
cm and 2 meter amateur bands; plus,
for the first time ever, both the mili-
tary and federal government land
mobile bands. Both automatic and
manual search, lockout, scan delay,
direct channel access. Even a liquid
crystal display. Flexible antenna, ear-
phone, AC adapter/battery charger
and carry case are included.

Your Bearcat Dealer
wants to hand you
an earful.

See your Bearcat Dealer
now for a demonstration of the
amazing Bearcat 100. Get complete
information about the world’s first
hand-held, no crystal scanner.

SCAN’s 30,000 members know what
others miss! Insider news. Frequency
info. Tech tips. Awards. SCAN Magazine
. . . and more! Send $10 for 1-year mem-
bership to the Scanner Association of
North America, 1 1 1 East Wacker Drive,
Chicago, IL 60601.

Electra Company

BEARCAT.

SCANNERS

To find out more about where to buy the Bearcat 100 or other Bearcat Scanners, call 800-S-C-A-N-N-E-R toll free.

Division of Masco Corp. of Indiana
300 East County Line Road
Cumberland. Indiana 46229

CIRCLE 5 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

vert the signal on channel-B and can thus
look at the difference of the two signals.

The third control-grouping contains a
BNC input-jack for the trigger source or
for the source of horizontal deflection.
The source is selected by a 4-position
pushbutton switch (a, b, ext, or ext 4-
10). Above the pushbuttons is the time/
div control, which, like the ampl/div
control, consists of two knobs. The outer
knob adjusts the sweep rate from 0. 1 /jls/
div to 0.5 sec/div in a 1-2-5 sequence. As
before, the center control allows you to
continuously vary the sweep rate. The
defl position of the time/div control al-
lows you to use the scope in the
horizontal-deflection mode. The horizon-
tal deflection can be increased by a factor
of ten by pulling out the horizontal chan-
nel’s position control.

Along the top of the third control-
grouping is a 5-position pushbutton
switch that selects the trigger mode and
the polarity of the trigger. A level con-
trol lets you vary the level of the wave-
form on which the scope will trigger.

Other features

Located on the back panel is a BNC
input for Z-axis (intensity) modulation.
That allows you to feed a periodic signal
to the control grid of the CRT, which will
brighten or dim the trace and give a third,
Z, dimension. Periodically brightened
spots can be used as markers to time-

calibrate the main waveform. A signal
that is applied to the external Z-axis input
can also be used to cut off the CRT at
selected parts of the trace (much like the
retrace blanking signal that is fed to the Z
amplifier).

The PM 3215 is very well documented.
There are three manuals supplied — an op-
eration manual, a service manual, and a
manual for the attenuator probes. All of
the manuals are very well written. The
operating manual is 87 pages long and is
written in three languages (about 25 pages
for each). The operating manual includes
a brief check-out procedure that is es-
pecially useful.

The service manual (written entirely in
English) is over 100 pages long. It is
comprehensive and includes full schema-
tics, circuit descriptions, corrective-
maintenance procedures, printed-circuit
board layouts, parts lists, and more. In
short, the manuals give you all the in-
formation that you need to operate and
service the scope. However, if you do not
wish to make your own repairs or adjust-
ments, there is also a list of worldwide
sales- and service-centers.

All in all, the PM 3215 is a high-quality
50-MHz dual-trace scope that would be a
welcome addition to just about any
benchtop. The suggested $1195 list price
is just about what you would expect to pay
for such a professional piece of test equip-
ment. R-E

Vector PI 84-7
Slit-N-Wrap
Tool

CIRCLE 104 ON FREE INFORMATION CARD

TWO MOTORIZED WIRE- WRAPPING TOOLS,

the PI 84-7 (shown in photo above) and
P180-7 Slit-N-Wrap tools from Vector
(12460 Gladstone Avenue, P.O. Box
4336, Sylmar, CA 91342) represent a
logical extension of their line of con-
venient and effective wire-wrapping
tools. Of course, those two models make
the same reliable connections as Vector’s

FIRST QUALITY COMPONENTS - NOT MAIL ORDER “SECONDS”

cam actuated, true zero
insertion - tin plated solder
tail pins - capable of being
plugged into dip sockets,
including wire wrap.

Stock No. of

No. Pins 1-9 10-49 50

11055 24 4.98 $4.35 $3.90

11056 28 5.15 4.50 4.05

11057 40 6.81 5.95 5.35

11058 64 12.02 10.50 9.45

IC-KOOLERS' from
UNITRACK* dissipate
over 2 watts of heat from

IC’s. producing longer life oooor
and better performance. f
Just push IC-Kooler on -
heat is collected from top
and bottom of 1C and
dissipated. Won't shake

Stock No. Pin*

No. in 1C Pries
22225 14 $.29

$79

DIGITAL MULTIMETER

Single rotary switch opera-
tion. Large, easy to read .5"
3-'/ 2 digit display. 800 hours
operating life with single9v
battery. Seven functions—
(DC Volts, DC Amps. Ohms,
AC Volts. AC Amps. Diode
and Resistor Junction, Aud-
ible Continuity Check).

Stock No. Carrying case with

62504 belt loop $9.95

WILD ROVER

Touch switch capsule.

Operating motion is .005" without the
use of a levered arm. Extremely fast on
and off with low noise. Normally open -
rated 1 15 VAC, 1.6 amp-30 milliohm re-
sistance - .61 5 radius by .1 60 thick.
Stock No. 1-9 lO&Up

12098 $1.42 $1.28

60/40 ROSIN CORE SOLDER

Stock

50075

50076
5007 7

50078

50079

50080

062

032

Length Weight
(feet)

Tl WIRE

WRAP

SOCKETS

Tin plated
phosphor bronze
contact -3 wrap

Send for Free Catalog -
over 1 1 00 parts.

Tl LOW PROFILE
SOCKETS

Tin plated
copper alloy
688 contact pins
with gas tight seal.

Stock

No.

No Pins

, 1-99

-499 500

No. No Pins

1-24 25-99

999

11301

$.40

$.36 $.30

11201

$.10 $.09

$.08

11302

.59

.54 .45

11202

.14

.13

.12

11303

.64

.58 .48

11203

.16

.15

.14

11304

.73

.66 .55

11204

.18

.17

.15

11305

.99

.90 .75

11205

.20

.18

.16

11306

1.12

1.02 .85

11206

.22

.20

.18

11307

1.25

1.14 .95

11207

.24

.22

.20

11308

1.52

1.38 1.15

11208

.28

.26

.25

i 11309

2.05

1.86 1.55

11209

.40

.37

.33

ELPAC POWER SUPPLIES - DC/DC CONVERTERS

Stock No. 13801
- “Floppy Disc”
Power Supply For
Winchester Drives (!

$109.°°

13801-1 Datasheet
for 13801 ... .25

SINTEC
Stock No.
300 MW Type

13825

13826

13827

13828

13829

13830

1 .5 W TYPE:

13831

13832

13833

13834

13835

13836
13825-1

ELPAC Input Output Output Dimensions

No. Voltage Voltage Current (HxWxD)

(VDC) (VDC) (MA) in Inches
CB3801 3. 0-7.0 12±0.6 0-25 .48x.51x3.05 $ 7.95

CB3811 3.0-7. 0 -1 2+0.6 0-25 .48x.51x3.05 7.95

CB3802 3. 0-7.0 15±0.7 0-20 .48x.51x3.05 7.95

CB3812 3.0-7.0 -15±0.7 0-20 .48x.51x3.05 7.95

CB3804 3.0-7. 0 28±0.7 0-10 ,48x. 51x3.05 7.95

CB3814 3.0-7. 0 -28±0.7 0-10 .48x.51x3.05 7.95

Price

DATA SHEET FOR DC/ DC CONVERTERS 25

Special of the Month!

ov* f

,ceP’

59002 Kit $37.50

59003 Assembled Unit $59.50

.For more detailed information call for catalog

ELPAC POWER SUPPLIES - SOLV SERIES FULLY REGULATED

Output

SINTEC ELPAC Output Current
ock No. Part No. Voltage Rating

3802 SOLV15-5 5 3.0A

3803 SOLV15-12 12 1 5A

3804 SOLV15-15 15 1 ,2A

3806 SOLV15-24 24 0.75A

3808 S0LV30-5 5 6.0A

3809 SOLV30-1 2 12 4.0A

3810 SOLV30-1 5 15 3.3A

3812 .SOLV30-24 24 2.0A

32-1 Data Sheet for SOLV Series .

4-7/1 6x4x2
4-7/1 6x4x2
4-7/16x4x2

4- 7/16x4x2

5- 5/8x4-7/8x3-3/16
55/8x4-7/8x3-3/1 6
5-5/8x4-7/8x3-3/16
5-5/8x4-7/8x3-3/16

OVP Price

Fixed included < $39.95
Fixed included 39.95

Fixed included 39.95

OVP-4 59.95

OVP-4 59. 9S

OVP-4 59.95

OK MACHINE AND TOOL •

1C INSERTION/
EXTRACTION KIT

Includes DIP 1C extractors and
inserters fo accommodate all ICs
from 14 to 40 pins Tools that
engage conductive surfaces are
CMOS safe and include ground-
ing lugs Stock No. $37 74

PIN FORMING TOOL

puts IC’s on their ^ i

. , — ,

true row to row ^ —

spacing. One side is

for .300 centers, Fnp tool overtor devices
on .600 centers. Put device in tool and
squeeze. MPW1 Stock No. 10200 $14.95
ONE TOOL DOES ' (ANT, -STATIC MODEL,

8 thru 40 PINS! Stock No. 1 1059 $1 2.95

SOCKET WRAP ID

DIP socket-sized plastic panels
with numbered holes in pin loca-
tions Slip onto socket before wire
wrapping to identify pins Also

them for location. 1C part
number, function, etc. Simplifies
initial wire wrapping, trouble-
shooting and repair

$1.82 per

13295-

13296-

13297

13298

13299

13300

13301

13302

13303

20 pin

24 pin

pack

1C EXTRACTOR

One-piece, spring steel con-
struction. Will extract all LSI, MSI
and SSL devices with 8 to 24
P ins - Stock No. <k 0

13313 $2. 1U

MODUTEC

Miniclamp AC Volt-Ammeter

allows singling one conductor out of
many without disarrangement.

Stock No. AC Amperes Price
1 3730 0-25A $39.50

ACCESSORY LINE SPLITTER

allows fast readings of AC power con-
sumption of plug in equipment with-
out separation of leads. ^

Stock No. 1 3727 $9 . 5

POCKET SIZED
BATTERY TESTER

for all types of small batteriesfrom
,1.35vto4.5v aj q qc

Stock No. 1 3733 Jp I O .
VOLT-I-CATOR

automotive diagnostic meter plugs
into lighter socket and indicates bat-
tery condition and charging rates.

Stock No. 13736 $15 .95
AC VOLTAGE TESTER

plugs into any 1 lOv service recept-
acle to check line voltage over 50-

150 VAC *-1/1 QR

Stock No. 13735 $ |

VOM-MULTITESTER

versatile Volt-Ohm-Milliammeter in
small package Q( -

$13. 95

D - 3

Stock No. 13729 -

Drawer Q Milford
CO. NJ 08848-9990

TOLL 800-526-5960

FREE in NJ (201)996-4093

We accept VISA, MC,

C.O.D., CHECK, or M.O.
•INCLUDE SHIPPING CHARGES-
0 to $100. -$3.00
$100. to $250. -$4.00
over $250. -$5.00

CIRCLE 82 ON FREE INFORMATION CARD

► HITACHI

Non-Linear Systems

fflWSl

=LUKI

H1CKOK

TRIPLETT

WESTON

PHILIPS

jty Qboata precision

LEADER

^HITACHI

A 30 MHz
SCOPE AT A
15 MHz PRICE

$C^CI95 DUAL TRACE %

W/DELAY "f

mzmjmxm v-3*

t «

B ill ... m*.

Price does not include probes.

Probes $50. a pair when purchased with
scope. $10. shipping within continental U.S.

INDUSTRIAL

TRAMQIQTflD

WAS 5249.

POWER SUPPLIES

• model

520B

Now with MI/LO Drive

Works in-circuit when
others won’t

identifies ail three tran-
sistor leads

Random lead connection

Audibly and visually in-
dicates GOOD transistor

MODEL

1601

$299 95

WAS 5359.

$319 95

WAS 5390.

MODEL

1650

» Isolated 0-50VDC, continuously
variable; 0-2 A in four ranges

i Fully automatic shutdown, adjust-
able current limit

i Perfect for solid state servicing

1 Functions as three separate suppl-
ies

i Exclusive tracking circuit
i Fixed output 5VDC, 5A
i Two 0 to 25VDC outputs at 0.5A
i Fully automatic, current-limited
overload protection

All Hitachi Oscilloscopes feature
2 year parts and labor warranty.

WE CARRY
A FULL LINE
OF HITACHI
OSCILLOSCOPES

CALL FOR
OUR PRICES

FUNCTION GENERATORS

M ?„1„ EL $ 179 95

WAS 5229.

M 3°S l $ 319 95

WAS 5394 .

MODEL 3010

■ Sine, square and triangle output

■ Variable and fixed TTL outputs
» 0.1 Hz to 1 MHz in six ranges

■ Push button range and function selection

■ Typical sine wave distortion under
0.5% from 1 Hz to 100kHz

SWEEP FUNCTION
MODEL 3020

■ Four instruments in one package —
sweep generator, function generator,
pulse generator, tone-burst generator

■ Covers 0.02Hz-2MHz

■ 1000:1 tuning range

■ Low-distortion high-accuracy outputs

Sea *189 95

1 “ WAS 5238.

MODEL 830

■ Automatically mea-
sures capacitance
from 0,1 pF to 200mF

■ 0.1 pF resolution

■ 0.2% basic
accuracy

■ 3 V 2 digit LCD display

CAPACITANCE METERS

$15995

WAS 5192.

MODEL 820

Resolves to 0.1 pF

4 digit easy-to-read
LED display

Fuse protected
against charged
capacitors

Overrange indication

BECKMAIM

DIGITAL

MULTIMETERS

ALL IN STOCK
CALL FOR PRICES

E me

■ . aSSSS^ 74

26 WEST 46th STREET, NEW YORK, N.Y. 10036 212-730-7030

THE TEST EQUIPMENT SPECIALISTS

ADVANC

ELECTRONIC

RADIO-ELECTRONICS

other Slit-N-Wrap tools but they also have
some desirable features that can be es-
pecially advantageous.

With the PI 84-7 and PI 80-7, there will
be no more over-wrapped or under-
wrapped connections. You simply dial-in
the desired number of wraps, and each
time the trigger is squeezed, the tool de-
livers that pre-set number of turns and
then stops ! Anyone who does more than a
minimum amount of wire-wrapping will
really appreciate the value of an automa-
tic tums-counter.

Before examining those tools farther,
let’s distinguish between them. The only
different between them is the type of wire
that they use. The PI 80-7 is set up for use

with 28-gauge copper wire coated with
polyurethane and nylon insulation. That
is the “standard” wrapping wire, which
also may be soldered without stripping.
The P184-7 uses 28-gauge silver-plated
copper wire with a Tefzel (Kynar and
Teflon) insulation. The Tefzel is a bit
thicker (.005 inches), but it takes the best
features of its component parts, resulting
in a tough insulation that helps to reduce
crosstalk. Other than using different
types of wire, both models are alike.

Certainly, Slit-N-Wrap is a well-
known wire- wrapping technique. Using
that method, it is unnecessary to strip the
insulation from the wrapping wire before
it is applied to the wire- wrap post. The

STUDIO SPEC "MAGNIFIER LAMP

AT s 59. 95 YOU
CAN'T AFFORD TO
BE WITHOUT IT

This quality all-metal construction
| UL recognized lamp uses a standard
22 W fluorescent cireline bulb (the
| bulb is included!). Features of this
great buy include a polished, dis-
tortion-free glass magnifier (X3); a
| 4-way, all metal clamp bracket; a
full 45" reach. The lamp is available
in two colors: Ivory or chocolate
brown.

You must agree, it’s a steal at only
$59.95 ea. (plus shipping). If you
buy 5 or more, it’s only $54.95 (plus
shipping). Order No. MX114.

Shipping is only $5.00 ea. in the
continental USA.

SPECIAL BONUS! If v ou buy one or more of the
magnifier lamps, you can get our LTS103 bench lamp for only $10.95 ea.
(plus $2.80 ea. shipping). The LTS103 is UL listed to 100 W, utilizes a
porcelain socket, and includes mounting brackets.

To Order Call Toll Free

( 800 ) 423-5336

Calif. Toll Free

( 800 ) 382-3663

Local

( 213 ) 701-5848

ELECTRONICS

A DIVISION OF ALLIANCE RESEARCH CORPORATION

“OUR SERVICE MAKES THE DIFFERENCE”

18215 Parthenia Street, Northridge, CA 91325

QTY ORDER NO.

COLOR

PRICE

SHIPPING

EXT

85-MX114

$59.95*

$5.00

85-LTS103

10.95

2.80

85-MX115-FL

5.95

2.00

*Only $54.95 for 5 or more

TOTAL

Credit Card #

Exd. Date

Name (Please print)

Signature

CIRCLE 37 ON FREE INFORMATION CARD

tool automatically slits the insulation as
the wire is wrapped but the insulation
remains intact between wraps. Thus, it is
possible to wire from post-to-post (daisy-
chain style) without cutting the wire and
starting fresh at each one or having to
worry about wires shorting to each other.

The amount of tension on the wrapping
wire is very important. Too little tension
will result in a poor electrical and me-
chanical connection. Too much tension
can cause wire breakage and poor me-
chanical stability. Vector provides ex-
plicit and easily-followed instructions for
properly setting the two adjustments
which determine the tension on the wire
as it is fed through the tool. Once those
adjustments are made, the tension need be
checked only occasionally. During our
tests, the tension remained constant after
the initial adjustment.

Setting the number of turns to be made
is only a matter of setting a small dial on
the top of the machine. For 28-gauge
wire, 7 turns are recommended. Avail-
able settings range from 3 to 9 and r,
which is a free-running mode that causes
the tool to wrap continuously without
counting or stopping — as long as the trig-
ger is held. In addition, there is a small
three-position toggle switch that engages
or disengages the electronic counting-
mechanism or disengages the trigger to
prevent accidental turning when you are
working on the tool.

Another convenient feature of the tools
is that the free end of the first wrap need
not be held — it is automatically secured.
That provides a further advantage not
only in convenience, but in speed as well.

So that you can keep track of the wiring
in wire-wrapped circuits — it can get
rather unwieldly at times — the insulated
wire is available in different colors. At
this time, four different wire colors are
available with polyurethane-nylon in-
sulation, while six colors are available
with Tefzel insulation. The tools are de-
signed to make changing the wire quite
painless. Even changing the slitting-
wrapping bit is easy, though with an anti-
cipated life of 7,000 seven-turn wraps,
the typical operator would not need to do
that for some time.

During our testing of the PI 84-7, it was
found to be fast and effective. Further, the
pistol-like tool was balanced and shaped
to reduce fatigue even when used for long
periods of time.

The tools are packaged in complete
kits. In addition to the wrapping tool,
each contains an AC power supply, a
large roll of wire, a cutting-format tool,
and an adjustment tool. Also included are
a weight for adjusting wire tension, a
small supply of wrap posts, an Allen
wrench and spare set-screws, and even a
push pin that may come in handy when
threading the wire. Of course, there is a
thorough instruction booklet that covers
not only the tool itself, but general wire-
wrapping techniques.

Altogether, the Vector PJ84-7 and
PI 80-7, which sell for $175 each, are
well-designed, effective and well-
package. Using either or both of these
tools will provide increased efficiency
and maximum assurance that the wraps
are mechanically and electrically sound.
The PI 80-7 and PI 84-7 are worthy addi-
tions to the Slit-N-Wrap line. R-E

System Saver Protection
Device for Apple II

Computers

CIRCLE 105 ON FREE INFORMATION CARD

A NUMBER OF TODAY’S SMALL COMPUT-

ers, such as the members of the Apple II
family, do not use forced-air cooling. Be-
cause of their relatively low component
count, and the fact that most of the IC’s
are the low-power Schottky type, they
can get by with convection cooling
through ventilation slots in the computer
case.

The problem with the Apples , though,
is that their seven or eight expansion slots
encourage the addition of additional
boards that contain additional heat-
producing components. By the time
you’ve added a disk-controller card, extra
RAM, an 80-column display board, and
I/O capabilities, it starts to get pretty
warm inside the case.

Heat, as you are no doubt aware, is the
enemy of electronics components. It
shortens their lives and can frequently
cause IC’s to act erratically. (So that’s
why my disks got garbaged last night!)

Kensington Microware Ltd. (300 E.
54th St., New York, NY 10022) has
come up with a solution to the “baked
Apple ” problem; it’s called the System
Saver.

The solution

The System Saver is really a very sim-
ple device. It attaches to the left side of
the computer, over the ventilation slots
there, and contains a fan that pulls 15-
cubic-feet-per-minute of air through the

computer, across the area where the
accessory boards are located. That flow
of air carries away the heat generated by
the boards and keeps the computer operat-
ing comfortably.

In operation, the fan is quiet enough to
become completely unobtrusive after a
little while, and the air exhausted is only
mildly warm to the hand. What really
matters is that the computer runs cool,
and can be operated for extended periods
without fear of overheating something in-
side and causing the system to crash.

The device offers several convenience
features as well. At its rear are two three-
prong electrical outlets rated at eight
amps (total). They allow you to plug in
your monitor and printer and, by throw-
ing the rocker switch — which contains a
pilot light, by the way — at the front of the
unit, to turn those two pieces of equip-
ment, and the computer, on all at the same
time.

The System Saver provides another
benefit in that it has a surge suppressor
built in; voltage spikes that may appear on
the power line are clipped off at a level of
130-volts RMS (175-volts DC). That will
help keep glitches out of the system.
You’ll appreciate that, especially if you
live in an area where spikes and surges are
a way of life.

And, to put the icing on the cake, there
is also a “pi ’’-type RF filter to prevent
continued on page 38

SATELLITE TELEVISION SYSTEMS

VARIETY IS THE NORM, NOT THE EXCEPTION.
Placed over the equator, by the U.S. and Canada,
are 12 satellites carrying over 80 channels of TV
programing. First run and classic movies, sports,
specials, childrens shows and night club acts.
Super stations from New York, Atlanta and
Chicago. Adult films. Network broadcasts from
ABC, CBS, NBC and PBS. Channels dedicated to
health, medicine, science, religion, news, weather,
financial information and live coverage of
congress. Even video music in STEREO. There are
channels dedicated to Pop/Rock and Country
music. Yours with the push of a button and the
twist of a knob on your TRITON satellite system.

perfectly clear, we have a technical staff standing
by on our TOLL FREE line to answer any questions
that you may have. What a great feeling ! ! !
Watching satellite TVfrom a system YOU installed

THE TIME TO ACT IS NOW. TRITON has all

systems IN STOCK for immediate delivery. Shipping
is done by motpr freight and UPS, depending on size
and weight. Our shipping staff is alert and efficient,
assuring you quick, complete shipments at the lowest
possible cost. Many systems can be shipped to you for
less than $100.00

ANTENNAS AS SMALL AS SIX FEET in diameter
will deliver a picture that is quite watchable in
most of the U.S. Some areas do require larger
antennas to view all channels. TRITON carries
complete systems to suit your individual need.
Systems are available for ground or roof
mounting with antennas constructed of aluminum,
fiberglass or plastic. Optional equipment includes
programable antenna positioners, wireless remote
control and stereo. Prices start as low as $1395.00

INSTALLATION IS SIMPLE. Most people who
purchase our systems do their own installations.
You need no special tools or skills. Instructions,
aiming coordinates and alignment instruments
are provided with each system shipped. Just in
case there is any part of the procedure not

DEALERSHIPS ARE WELCOME. We at TRITON
would be pleased to discuss dealership opportunities
with the established satellite dealer as well as
those who are thinking about selling satellite
equipment. National advertising, fast product
delivery, lead generation and technical suport are
only a few reasons to choose TRITON as your
satellite equipment distributor.

TO ORDER your TRITON satellite system, just
phone. To make purchasing quick and simple we
will accept MASTERCARD and VISA on all systems
and accessories. Sorry, no charge cards on dealer
sales. All systems and components carry a full one
year warranty. | n NEW Y ORK

TRITON MARKETING Corp. 212 345-8000

679 REMSEN AVENUE Outside NY

BROOKLYN, N Y 1 1236 800 221-6535

CIRCLE 54 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

You

around*

When you <lo. you'll probably pick (11%
lou can 9 ! afford to settle for
less when it conies to something like
electronics trai n i n g that could
affect your whole life.

you learn and review the basics —
perform dozens of experiments.
Plus, you use a 3-in-l precision
Multimeter to learn testing,
checking, analyzing!

W hen you shop around for

tires, you look for a bargain.
After all, if it’s the same brand,
better price — why not save money?

Education’s different. There’s
no such thing as “same brand!’ No
two schools are alike. And, once
you’ve made your choice, the
training you get stays with you for
the rest of your life.

So, shop around for your
training. Not for the bargain.

For the best. Thorough, profes-
sional training to help give you
pride and confidence.

* * *

If you talked to some of our
graduates, chances are you’d find a
lot of them shopped around for
their training. They pretty much
knew what was available. And they
picked CIE as number one.

Why you should shop
around yourself.

We hope you’ll shop around.
Because, frankly, CIE isn’t for
everyone.

There are other options for the
hobbyist. If you’re the ambitious
type — with serious career goals in
electronics — take a close look at
what we’ve planned for you at CIE.

When you build your own
5 MHz Triggered-Sweep,
Solid-State Oscilloscope

you take your first real professional
step. You use it as a doctor uses an
X-ray machine — to “read”
waveform patterns. . .
lock them in... study, understand
and interpret them!

When you get your
Digital Learning
Laboratory you’ll be into
digital theory — essential
training today for anyone

All this training takes effort.

But you’ll enjoy it. And it’s a real
plus for a troubleshooting career!

Do you prepare for
your FCC License?

Avoid regrets later. Check this
out before you enroll in any
program.

More than half of CIE’s
courses prepare you for the
government-administered FCC
License exam. In continuing
surveys, nearly 4 out of 5 CIE
graduates who take the exam get
their Licenses!

Associate Degree

Now, CIE offers an Associate in
Applied Science Degree in Electronics
Engineering Technology. In fact, all or
most of every CIE Career Course is
directly creditable towards the
Associate Degree.

Shop around. ..but send
for CIE’s free school
catalog first!

Mail the card. If it’s gone, cut
out and mail the coupon. If you
prefer to write, mention the name
and date of this magazine. We’ll
send you a copy of CIE’s FREE
school catalog — plus a complete
package of independent home study
information! For your convenience,
we’ll try to have a representative
contact you to answer your
questions. Mail the card or

coupon — or write:

CIE, 1776 East 17th St.,

Cleveland, OH 44114.

1 PJ Cleveland Institute
I E of Electronics, Inc.

1776 East 17th Street, Cleveland, Ohio 44114

□ YES... I’m shopping around for
the right kind of career training in
electronics troubleshooting — and CIE
sounds well worth looking into. Please
send me my FREE CIE school catalog
— including details about the Associate
Degree program — plus my FREE
package of home study information!

Print Name

Address Apt

City

State Zip

Age Phone

(area code)

Check box for G.I. Bill information:
□ Veteran □ Active Duty

Mail today!

RE-64

What you should
look for first.

Part of what makes elec-
tronics so interesting is it’s
based on scientific discover-
ies — on ideas! So the first
thing to look for is a
program that starts with
ideas and builds on them!

That’s what happens
with CIE’s Auto-Programmed®
Lessons. Each lesson takes one
or two principles and helps you
master them — before you start
using them!

How p ractical
is the training?

This is the next big important
question. After all, your career will
be built on what you can do — and
on how well you do it.

Here are ways some
of CIE’s trouble-
shooting programs
help you
get your
“hands-on”
training...

With CIE’s
Personal
Training
Laboratory. . .

who wants to keep pace
with the state of the art of
electronics in the eighties. With
CIE’s Digital Lab, you’ll be
applying in dozens of fascinating
ways the theory you’ve learned. For
example, you’ll compare analog
and digital devices. You’ll learn to
make binary to decimal conversions
and to work with semiconductor
devices and circuits. You’ll see how
digital equipment is vital in today’s
exciting, growing fields such as
security where digital
theory provides the
brains for space-age
alarm and protective
devices.

Of course, CIE
offers even more
advanced training
programs, too. But the
main point is simply this:

JULY 1983

RADIO-ELECTRONICS

NO MIXED

icondu'

quantities.

quantity

YOUR COMPLETE ELECTRONIC PARTS SOURCE!

| MOST ORDERS SHIPPED WITHIN 24 HOURS.

(Mo««c<>d! CALL OR WRITE FOR YOUR FREE CATALOGUE.

l V - X ~ y j COMPARE OUR LOW PRICES AND SAVE! Y#*mm

Soar Corporation 8050
Digital Multimeter

powm

OFF

CIRCLE 106 ON FREE INFORMATION CARD

f C - 1 Consolidated Electronics,
Incorporated

705 WATERVLIET AVE., DAYTON, OHIO 45420.
IN DAYTON, (513) 252-5662

CALL TOLL 1 - 800 - 543-3568

FREE TODAY! NATIONAL WATS

TELEX NO. 288-229

1 - 800 - 762-3412

electrical noise that may be present on the
lines from getting into the computer. The
filter is most effective from 600 kHz to 20
MHz, with an attenuation factor varying
from 30 dB to 50 dB . Its effect is strongest
at 2 MHz, which is close to the fun-
damental frequency of the computer’s
crystal clock.

Installation and use

Setting up the System Saver is so sim-
ple that I’ll quote the instructions here in
full. My comments appear in parenth-
eses.

1 . Attach System Saver to your Apple
II as shown. (A lip on the unit slips
over the top of the side of the com-
puter; the unit then just rests there.)

2. Disconnect your Apple II power
cord. You won’t need it any more.
(But I’d hold onto it if I were you —
you never know when it will come
in handy.)

3. Plug the System Saver's short
power cord into the back of your
Apple II. Plug System Saver's long
power cord into your wall outlet.
IMPORTANT: Leave your Apple
power switch permanently on.
You’ll never use it again.

4. Plug your monitor and printer in
System Saver's rear outlets.

5. You’re all set! System Saver's

front-mounted switch now controls
your System Saver, Apple II, moni-
tor, and printer.

That’s all there is to it. The System
Saver is in place and ready to protect your
computer from heat, power surges, and
line noise and, as far as I can tell, it does a
good job of it. The System Saver is color
matched to the Apple II, and can also be
used with the Apple Stand, if you use one.
$89.95 buys a lot of protection. R-E

THE NORTH AMERICAN SOAR CORPERA-

tion (1126 Cornel Avenue, Cherry Hill,
NJ 08002) is offering a digital multi-
meter, their model 8050, that has just
about all the ranges and functions you’ll
ever need for almost any kind of electron-
ic servicing.

Before we discuss its capabilities, let’s
look at its external features. The case is
made of strong plastic that should be able
to withstand some abuse. In the center of
the front panel of the case is a single,
recessed range-selector switch. The pow-
er switch is located at the upper left of the
case — that’s more convenient than hav-
ing it included on the range selector. (I
have more than once left my multimeter

continued on page 98

The Technician’s

Choice

Soar 8050 DMM

OVERALL

PRICE

EASE
OF USE

INSTRUCTION

MANUAL

PRICE/

/VALUE

■

2 I 3 |4 1 5 1 6

EQUIPMENT REPORTS

continued from page 33

CIRCLE 48 ON FREE INFORMATION CARD

NEW PRODUCTS

For more details use the free
information card inside the back cover

WAVEFORM ANALYZER, model SC61, is
the first instrument to automate completely
every conventional scope measurement for
the purpose of obtaining faster, more accu-
rate waveform analysis than is possible with
conventional scopes. The unit includes a digi-
tal readout on both channels for peak-to-peak

CIRCLE 131 ON FREE INFORMATION CARD

volts, DC volts, frequency, and time.

The automatic readout eliminates the time-
consuming graticule counting and calculating
for conventional scope measurements. That
total automatic readout is an exclusive. All
measurements are made through one probe,
available on both channels, eliminating any
extra time-consuming lead hookup. Peak-to-
peak volts, time and i/time are also featured
for any waveform section using a variable bar
Called “DELTA MEASUREMENTS.”

For a limited time, the model SC61 is priced
at $2995.00— Sencore, Inc., 3200 Sencore
Dr., Sioux Falls, SD 57107.

MODEM ENHANCER, the turboMUX, is de-
signed for owners of 21 2A modems, and dou-
bles the throughput of a 1 200-baud modem. It
provides two types of improvements: 2400-
baud full-duplex throughput, and the opera-
tion of a 2-channel statistical multiplexor.

The turboMUX has 2 channels. It attaches
via standard RS-232-C interfaces, to the

CIRCLE 132 ON FREE INFORMATION CARD

21 2A modem on one end, and to the data-
terminal equipment on the other. When one
channel is used, it accepts data at 2400 bits
per second. As a multiplexor, each channel
receives data at a minimum of 1 200 baud and
up to 2400 baud, for a total data throughput of
2400 bits per second. The turboMUX unit
compacts the data for transmission over dial-
up lines.

To double the 21 2A modem’s throughput,

CABLE TV

Buy Direct fr Save

SUPER SPECIALS
mm

40 CHANNEL
CONVERTER

$ 29 95

Advanced Solid State design and cir-
cuitry allows you to receive mid &
super band channels. Restores pro-
gramming to Video Recorders.

36 CHANNEL
REMOTE CONTROL
CABLE CONVERTER

$ 69 95

JERROLD 400
THE ULTIMATE CABLE TV
CONVERTER

60 CHANNEL
INFRARED
REMOTE
CONTROL

$ 129 95

Send $5 for Complete Catalog

DIRECT VIDEO SALES

P.O. BOX 1329

JEFFERSONVILLE, INDIANA 47130
CALL

1-81 2-282-4766

GET IBM -PC Capacity at a Fraction of IBM’ S Price!

New NETR ONICS 1 6 Bit EXPLORER 88-PC Kit
Starts at Just -Accepts All IBM Peripherals.

□ IBM compatible keyboard. ..$299. 95
+ T0.00 p&i.

□ IBM compatible color board. ..$299. 95
+ 10.00 p&i.

□ Additional ROM required. ..$35. 00.

Set your own pace! Invest and learn, at the rate
YOU want! Add to your EXPLORER 88-PC:

Deluxe heavy-duty steel cabinet that houses
either two 5Y4” floppies or a 5 ’A” hard disk
with one ftoopy. This cabinet features a
brush-finish front panel and a wood-grained
sleeve.

□ EXPLORER 88-PC Cabinet.. .$199. 95
+ 18.00 p&i.

A heavy-duty open frame power supply
with fan that can be used in your own cabi
net or installed into the Netronics cabinet is
available as follows:

□ 10 amp power supply for system + 2 flop-
pies. ..$149, 95 + 8.00 p&i.

□ As above + extra power for 1 hard disk...
$169.95 + 8.00 p&i.

□ IBM compatible disk controller board. Con-]]
trols four 5Va” floppy drives (w/2 drive
cable). Available wired and tested only...
$250.00 + 8.00 p&i.

□ Monitors and BIOS source listings: available
on either disk or hard copy at $35.00.

Please specify format and system required.

□ INTEL 8086/8088 user manual.. .$15. 00,
+ 1.50 p&i.

□ THE 8086 BOOK by RECTOR & ALEX
$16.00 + 1.50 p&i.

It’s true! Now you can enjoy the power of the
Intel 8088— the same microprocessor which
powers the IBM-PC— and run any program com-
piled for the IBM-PC.. .starting at only $399.95!

Take this easy, low cost way to learn 16-bit
technology! Two-board system features:

1. 8088 mother board with 5-slot expansion
bus; accepts any hardware designed for
IBM-PC; and

2. 64K memory board, expandable to 256K;
with IBM compatible RS232 communica-
cations port.

Any disk-operating system which works on the
IBM will work directly on the EXPLORER 88-PC,
and all programs compiled for the IBM will run
on it.

The system monitor ROM included in the Starter
system features a user-friendly operating system
that allows easy program generation and debug-
ging. The commands include display/modify
memory. ..display/modify registers. ..input/output
data to 1/0 ports. ..block moves. ..single-step
trace mode. ..go/run with optional breakpoint
and register reports. ..cassette load/save with file
labels. ..plus a complete system test program
that tests and reports condition of ROM, RAM.
cassette interlace, timer, DMA controller, inter-
rupt controller, and the communications port.
These test programs not only allow easy debug
ging of software but they serve as hardware and
software learning tools.

The EXPLORER 88-PC STARTER KIT includes a
mother board, memory///0 board, al components
needed, sockets for IC’s used, one 62-pin bus
connector and complete assembly/test instruc-
tions. All you need is a soldering iron, solder, a
power supply, and a standard RS232 terminal
(Netronics has 2 low-cost ones to choose from).
Explorer 88-PC Starter Kit. ..$399. 95
+ 10.00 p&i

□ (wired & tested, add $100.00)

□ Extra 62-pin connectors at $4.25 ea.

+ 1.00 p&i.

Use your own terminal with the EXPLORER 88-PC
or, if you plan to expand it to be fully IBM com-
patible, we offer our IBM compatible keyboard
and an IBM compatible color graphics board
(only available wired and tested).

ir- -

□ Special IBM compatible system: with key-
board, color graphics board, floppy disk
controller, 64K RAM, cabinet, standard
power suoply and a sinqle 5'A” floppy drive...
$1899.95 + 25.00 p&i.

IBM compatible hard disks, built-in modern
board, eprom burner, print buffer system plus
more will be available shortly.

Over 100 EXCLUSIVE Products and Kits—
including the ‘Speak Easy’ universal voice
synthesizer, a Diagnostic card with built-in
logic probe for the IBM-PC, terminals, moni-
tors, the ELF and EXPLORER 85 computers,
and much more, are described in our up-
coming catalog. It’s yours FREE if you check
here □

■i For Canadian orders!
[j please double the amount!
' of p&i shown. IBM-PC is a!
j registered trademark of|
J IBM Corporation.

p&i” stands for “postage and insurance ". f

CALL TOLL FREE 1 800 243 7428 for Charge Card Orders.

In Conn., call 203-354-9375, Conn. res. add sales tax.

TO ORDER BY MAIL, CHECK BOXES FOR PRODUCTS DESIRED AND MAIL ENTIRE AD TO:

ISN NETRONICS R&D LTD.

333 Litchfield Rd.. New Milford, CT 06776

OR Charge my □ VISA Q MASTERCARD
Exp. Date •

□ Amount enclosed
Acct. No.
Signature
PRINT NAME
Address

City

State

Zip

I -

CIRCLE 53 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

Digital

Features.

Analog

Prices.

Now you can get all the
measurement capability
you’ve been looking for
in a digital multimeter
for the price of an analog.

Priced as low as $59.95, the
Circuitmate™ Series DMMs
from Beckman offer a superior
combination of standard
features including:

• DC + AC volts

• DC + AC Amps

• Resistance

• Diode Test

• 0.8% or 0.5% DC Accuracy
(depending on model)

• Single Rotary Selection
Switch

Depending on the model you
choose— you can enjoy the
added capability and conven-
ience of 10 Amps AC + DC,
audible continuity checking,
hFE testing, capacitance and
conductance capability.

Get your hands on a
Circuitmate™ dmm today.

For the dealer nearest you,
write or call

Beckman instruments, inc.,
instrumentation Products,
2500 Harbor Blvd.,

Fullerton, CA 92634,

(714) 993-8803.

BECKMAN

the turboMUX unit uses a data-compaction
algorithm. For phone-line inconsistencies,
the turboMUX unit provides error detection
and re-transmission facilities.

The turboMUX is priced at $995.00. (At
$1 ,275.00, the turboMUX unit offers a 20-
channel statistical multiplexor that can oper-
ate with the 21 2A modem.)— Chung Tele-
communications, Inc., 4046 Ben Lomond
Dr., Palo Alto, CA 94306.

TIME-INTERVAL OSCILLOSCOPE, model
1726A, offers 50-picosecond accuracy and
10-picosecond resolution; it combines coun-
ter and oscilloscope technologies and has
the viewing and measuring capabilities of a
275-MHz oscilloscope, and the ease of use of
a time-interval counter.

CIRCLE 133 ON FREE INFORMATION CARD

The model 1726A uses a crystal-reference
time base (i.e., the counter measurement
technique) in conjunction with a CRT and
stable triggering circuits (i.e., the oscillo-
scope measurement technique). The com-
bination allows the model 1726A to display
the signal being tested as well as measure
the designated interval with up to 50-
picosecond accuracy. The hybrid technology
provides new measurement capabilities
(e.g., first-pulse measurements) with a
repeatability characteristic (± 30
piocoseconds) not offered by any other time-
interval measurement instrument.

The model 1726A is priced at $7675.00 —
Hewlett-Packard, PO Box 2197, Colorado
Springs, CO 80901 .

DC POWER SUPPLIES, model 7400
(shown), model 7401, model 7402, and mod-
el 7403, all feature large, bright, 3-digit LED
displays that indicate voltage or current. The
output of each model is uniform. Ripple is
held below 1 mA, line regulation is less than
5mV and 5mA, and load regulation is better
than ± 0.3% on voltage and ± 0.5% on
current. All models have constant voltage
and constant current outputs. If the load cur-
rent exceeds the established setting, the dec-
imal point in the LED readout blinks and the
unit stabilizes, i.e., the output current remains
constant while the output voltage changes by
whatever amount is necessary to accomplish
that.

The model 7400 delivers 0 to 25V to 1 .5A,
and is priced at $235.00. The model 7401 is 0
to 25V at 0 to 3A, while the model 7402 is 0 to
36V at 0 to 2A; both have the same price:
$275.00 each. The model 7403 is 0 to 36V at

CIRCLE 134 ON FREE INFORMATION CARD

0 to 3A, and is priced at $325.00.— North

American Soar Corp., 1126 Cornell Ave.,
Cherry Hill, NJ 08002.

BOARD, the EPROM Programming Board,
model EPB-MPF allows the user to program
all single-supply ( + 5-volts) 1K/2K/4K
EPROMS. Software stored in 2K bytes of
on-board ROM gives the model EPB-MPF
the capability to read, write, copy, test, and
verify desired program code. The software
also provides for restart, delete, and insert
operations using 4K bytes of on-board static
RAM as a buffer memory.

CIRCLE 135 ON FREE INFORMATION CARD

The model EPB-MPF’s features include:
2K bytes of ROM, 4K bytes of RAM, 24 para-
llel I/O lines, 24 pin zero-insertion-force sock-
et, 9-volt 400 MA power adaptor, complete
accessories to hook up the model EPB-MPF,
and a detailed operations manual.

The model EPB-MPF is priced at
$169.00.— Etronix, 14803 N.E. 40th Street,
Redmond, WA 98052. R-E

CIRCLE 78 ON FREE INFORMATION CARD

★★★★★★★★★★★★★★★★★★★★★ iririr - a- ★ ir ^ ^ w ir ★

2300 MHz VARIABLE

★★★★★★★★★★★★★★*★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★

ANTENNA KIT -

^ 32 WASHERS

V VN iwHjV v 31 SPACERS

\ MOUNTING BRACKET

\ Aio\ 6” RG 174 COAX

T CONNECTOR • 35” ROD
6V2” x 4” P.V.C. PIPE

2 DRILLED END CAPS • HARDWARE

POWER SUPPLY

is*

POWER TRANSFORMER
COURSE TUNE POT.
FINE TUNE POT.

3 ‘F’ CONNECTORS
RESISTORS & CAPS
LED WITH HOLDER
TERMINAL STRIP

P.C. BOARD
RF CHOKE
KNOB
WIRE

2 SWITCHES
4 DIODES
LM 317 REG.

WOOD GRAIN CABINET WITH SILK
SCREENED front and back $10.95 Extra

BUILT POWER SUPPLY $34.95

Complete
Down Converter
System

INCLUDES
ANTENNA KIT
POWER SUPPLY KIT
CONVERTER KIT

SPECIAL $49.95

QUANTITY
DISCOUNTS
Any Price in Adv.

10 pcs 12% off

25 pcs 18% off

50 pcs 25% off

100 pcs 30% off

1000 pcs 35% off

No Mixing for
Quantity Discount

DOWNCONVERTER

^★★★★★★★^ ★★★★★★★*★★★★★★★*************

PARTS CONVERTER

Converter P.C. Board / If” fT

Plated through holes »1

for stability $4.95 mr'S (ft r S^R95

Power Supply l “ c i BL

P.C. Board 2.95 fel mf j/9

MRF 901 2.00 \^W

NE02135 4.95 P.C. BOARD PRE-DRILLED

2835 Diodes 95 SOLDER PLATED WITH

•001 Chip PLATED THROUGH HOLES

Caps 10/3.95 FOR A MORE STABLE PIC-

Choke Set of 4 1.95 TURE. t/eou.'!

LM 317 Regulator 1.25 • • • • Harrun^^- ■

‘F Connectors 3 -MftF-961^fRANStST©R---

Chassis 50 2 HP 2835 Diodes

Wall Transformer 6 .001 Chip Caps.

12 VAC 700 MA....4.95 9 Resistors

‘U’ Bolt 95 4 Prewound chokes

BALUN 1 Electrolytic Cap.

75 to 300 ohm 1.95 1 Pre Made Probe

BALUN

for rabbit ears....2.95 ® ® (8) (S) (8) (8) ® (§) ® (8)

*RG 59/ U COAX
WITH CONNECTORS
FACTORY MADE

100 Ft $17.50

50 Ft 9.50

25 Ft 5.75

3 Ft 2.50

P.C. BOARD PRE-DRILLED
SOLDER PLATED WITH
PLATED THROUGH HOLES
FOR A MORE STABLE PIC-
TURE. tset+j ."

....■2/37 Ho T TfZPtM <> •■

2 HP 2835 Diodes
6 .001 Chip Caps.

9 Resistors
4 Prewound chokes
1 Electrolytic Cap.

1 Pre Made Probe

★ WIRED P.C. BOARD TEST-
ED, READY TO CONNECT TO
CAN WITH PROBE & CABLE
CONNECTOR ATTACHED.
$24.95

We will tune conver-
ter board for $12.50
trouble shoot

add 7.50

trouble shoot
power supply.. $12. 50

plus any parts needed.

We will accept telephone orders for Visa & Mastercard

No C.O.D. Orders

To Order Call 800-428-3500 317-291-7262

Complete Kit Weighs 10 pounds. Please add Sufficient Postage

6254 La Pas Trail
Indianapolis, Indiana 46268

ELECTROniC

PAinoouj i

SATELLITE TELEVISION RECEIVER

KITS

* to r°t> ,

The Electronic Rainbow Receiver consists of a receiver
with an external down-converter that mounts at the
antenna, feeds the voltage to the LNA through the coax
cable. The 4GHz signal is down converted to 70 MHz
and is fed through the RG59/U coax to the receiver.

Rainbow Kits are supplied with simple step by step in-
structions. All the circuits that you need expensive test
equipment to do are pre wired and tested. All printed
circuit boards have the outline of each part printed on
them.

RECEIVER FEATURES

Built in RF modulator • Detent
Tuning-3.7 to 4.2 GHz • Variable
Audio-5.5 to 7.5 MHz • Invert Video
• Channel Scan • Voltage monitor-
ing • Meter output • Remote Tuning
SPECIFICATIONS:

Single Conversion Image Rejection
Downconverter • Threshold 8 db
CNR • IF Bandwidth 24MHz • Out-
put IV Audio and Video • IF Fre-
quency 70MHz • Video Bandwidth
4.5MHz • Size 3V2 M Hx8 1 /2 ,, Dxll 1 /4 ,, W

Complete Satellite TV Receiver

KIT #1 — Contains:

• Mainboard • Tuning Board • Down-
converter Board • Modulator Board

• All parts needed to complete receiver

• Down Converter built in case.

• Cabinet, attractive black brushed ano-
dized metal with silk screened front
and back for a professional look

• 70 MH2 Filter is pre-wired and tested.

• Complete instruction
Manual.

KIT # 2 — Board Kit Contains:

• Main Board • Tuning Board • Down-
converter board • Modulator Board

• Parts List, assembly and alignment
manual

• 4GHz local oscillator and 70MHz filter
is pre-wired and tested.

$129.00

Instruction manual. Contains printed
circuit board layouts, parts placement,
and alignment instructions. QQ

-@5k about
g uatanteed
to pl&y

We will accept telephone orders for Visa & Mastercard

No C.O.D. Orders

To Order Call 800-428-3500 317-291-7262
Complete Kit Weighs 10 pounds. Please add Sufficient Postage

6254 La Pas Trail
Indianapolis, Indiana 46268

ELECTROfllC

Rmimouu i .

CIRCLE 45 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

A bench full of dragons

and no relief? __

Send in old reliable Keithley 179A. It could help you save the game. Get the high-
performance accuracy you need today, and field-installable IEEE-488 compatibility you’ll
need soon. Our oversize LED is easier to read. And non-sinusoidal waveforms won’t throw
you a curve with our TRMS. Here’s your workhorse Portable/Bench DMM at a price that
won’t strike out your budget. Keithley DMMs and Thermometers. The Dragon Slayers.

KEITH LEYl

Write Tom Hayden for your free, frameable 9x12" dragon poster. Keithley Instruments, Inc., 28775 Aurora Road, Cleveland, Ohio 44139.
^ Phone 216-248-0400. Telex: 98-5469. _

42 CIRCLE 36 ON FREE INFORMATION CARD

179A Features

• Five full functions

• lOpV sensitivity

• 20A capability

• 0.04% DCV accuracy

• HI-LOQ

• Field-installable
battery pack

• Field-installable
IEEE-488 Interface

• $379

Price U.S.A. only.

IF YOU WATCH ANY “SCIENCE FICTION,’’ EITHER ON TV

or at the movies, you have a pretty good idea of
what’s Hollywood’s concept of the car of the
future — a sleek sports model with enough computer
screens and controls to make even a Boeing 767
cockpit look like a child’s toy.

But researchers are hard at work trying to separate
the science from the fiction. A Sunnyvale, California
inventor and a major Japanese automobile-
manufacturer — in independent efforts — are bringing
us closer to the day when you can equip your car
with an automotive navigation-computer to guide you

Computers are finding more
and more applications in the
car, and soon one will even
be able to tell you where
you are and where you are
going. Here’s a look at the
automobile

navigation-systems of the
not-too-distant future.

DANNY GOODMAN

is 0 1J5

jjlliiiii

JULY 1983 S

RADIO-ELECTRONICS

through unfamiliar territory. We are not
talking about the Mercedes-Benz system
that you might have read about; that sys-
tem relies on communication between
your car and central traffic computers and
requires roadbed cables and sensors. The
navigation systems we’ll be looking at
consist of self-contained computers and
sophisticated optics systems that will,
among other things, eliminate the folded
mess of roadmaps in your glove compart-
ment.

Ready applications

If you frequently travel on business,
you’ve probably arrived in a new or un-
familiar city armed with little knowledge
about it other than the address of the com-
pany you’re there to visit. Arriving at the
car rental counter, you first ask for an area
map that, to your dismay, features only a
sketch of the main roads. Asking the
agent behind the counter draws a blank as
to the location of the company or the
small industrial-park street on which it is
located.

With a navigation system designed into
every car in the agency’s fleet, however,
the agent could preprogram a small film
pack that will display a map on the car’s
video screen; that map will show both
your present location and the location of
your appointment. When you’re done
with the business call, the computer could
show you how to get to your next appoint-
ment, or perhaps a local restaurant or your
hotel.

Preprogramming routes on a map could
save time and money for trucking compa-
nies and local delivery services. The most
efficient routes for each driver could be
defined by the company’s loading-dock
computer based on the listing of deliver-
ies to be made that day. Then each driver
could plug his route module into the
truck’s computer and follow the direc-
tions. The same on-board computer could
also be used to determine each driver’s
fuel efficiency and monitor how closely
the driver follows the prescribed sched-
ule. A long-haul trucking company could
use the same computer-encoded film
pack in an office version of the navigation
computer to determine the best route for a
potential customer, and then quote a price
based on actual operating costs that will
be incurred over the route.

The system should also prove quite
helpful in your family car. Trouble with
one-way streets or tricky expressway en-
trances would be a thing of the past as the
computer could help you pinpoint those
easily. And cross-country drives would
be much more fun since the computer
would be able to call up detailed maps of
cities and towns for those impromptu side
trips. Moreover, you’ll never really be
“lost” because the computer keeps con-
stant track of where you are and what
direction you’re going: just check the
screen map for your location in relation to
some distant landmark.

FIG. 1— A TOUCH-SENSITIVE flat-panel screen
displays a full-color area map that shows your
location and destination

The Navigator

Perhaps the most sophisticated system
is being developed by Michael J. Alton
and his company, Omni Devices, Inc.
(845 Roble Dr., Sunnyvale, CA 94086)
Although the system, called The Naviga-
tor , looks like something out of the 21st
century, it is revolutionary only in the
sense that it combines existing
technologies — fiber optics and
computers — in a new application. The re-
sult is a touch-sensitive flat-panel screen
that displays a full-color area map indicat-
ing your location and destination (see Fig.
1). As you move toward the destination,
your position on the map changes, and the
screen zooms tighter on the map, produc-
ing increased detail over a smaller area.

Figure 2 shows how the The Navigator
works. The light source consists of multi-
ple bulbs, reflectors (to intensify the light
in one direction), and color filters (ex-
plained later). Using many small bulbs
instead of a single, high-intensity bulb
helps disperse heat better. A single bulb
would probably require space- and
power-consuming forced-air cooling.
The multiple light- sources are blended
into a single projection beam using the
coalescing fibers.

Next, the light passes through a con-
densing lens, followed by an LCD matrix
that is under control of the computer. The
matrix is where variable images — your
location, destination, alphanumeric
readouts, etc. — are added. Just as the
electronically activated display-segments
in an LCD watch block light from travel-
ing to the reflective silver-gray back
plate, images created and positioned by
the computer in the LCD matrix of picture
elements (pixels) will block light from
passing any farther — thus making a sha-
dow appear on the display screen. The
prototype system uses a 32 x 32 pixel
matrix, but the projected resolution for
the production version is 128 X 128
pixels.

The film contained in the film cartridge
plays a multiple role in the system. In
addition to its obvious purpose of provid-
ing the map images that appear on the
dashboard screen, the film is also con-
tains the software that tells the computer

all about the area you’re traveling
through.

Map images are about the size of a
35-mm negative, and a single cartridge
can hold as many as 400 separate map
frames — enough to cover quite a large
section of the U.S. for long-distance
travel. But some frames contain solid
“pages” of computer data (we’ll see in a
moment how the computer reads the
data). The data frames hold not only
“raw’ ’ data like street names and number
ranges or hotel and restaurant locations,
but also data the computer needs to follow
a given street on the map: where the street
starts, what color it is on the map, its
direction of travel, length, etc. That data
is important because in locating a precise
address on a map, the computer es-
sentially “walks up” the street. Text-like
data (streets, hotels, etc.) would be con-
verted to LCD matrix characters for dis-
play on the dashboard screen. Other
coded data including data addresses (that
is, where on the film other related data
can be found) are implanted on the map’s
“black areas;” those areas include
streets, boundaries, and frame edges. A
film cartridge reportedly has space for six
gigabytes of information.

To achieve the affect of zooming in on
an increasingly smaller area as you
approach your destination, the system us-
es motorized lenses in a sliding bellows-
type arrangement. Each map will offer
between four and eight different levels of
magnification.

After it passes through the lenses, the
map image passes through a beam split-
ter. A small portion of the light is passed
straight through, via resolution-
intensifying fibers, to film-reading sen-
sors capable of handling a minimum reso-
lution of one thousand lines per inch;
those sensors are connected to the compu-
ter. The computer correlates what its sen-
sors “see” with the previously obtained
computer data to further reposition the
zoom lens and variable objects on the
LCD matrix. The computer “looks” for
color images on the map to help it track
exact locations. Instead of using ex-
pensive color sensors, the computer con-
trols rapid sequencing of the multiple
bulbs at the light source through their
respective color filters. Thus, simple sen-
sors in sync with the light-source bulbs
can detect which color is being passed at
any point on the map.

The majority of the map image light is
reflected up through projection fibers in
such a way that the screen image is di-
vided into small pieces like a checker-
board. The fiber bundles are attached to a
lens plate which in turn projects the seg-
ments onto a plastic display screen. The
prototype 8-inch-square screen consists
of 64 one-inch square segments. That
flat-screen projection system is much
more space efficient and safer in an acci-
dent than the traditional, long-necked
cathode-ray tube (CRT) display.

READBACK FIBERS

READBACK

SENSOR(S)

projection

niSPCAV SCREEN /

VIEWING SIDE AREA

jba§e5SS

COALE sC ' NG
FIBERS \

lUT\ON i

Vv6t« S

>^POS'f' OH

c p,R-[R'OGt

,rAG^' 06E

OONO^tcO 1 fW*

no. i — iraracn o i nuo i unc ot i ne navigator, in me more recenx version, me siiamg Tiim-canriage nas
been replaced by a sliding bellows-type zoom-lens system.

Another feature of the display assem-
bly is that readback sensors allow the
screen to become touch-sensitive. When
used in conjunction with screen menus
(see Fig. 3), the sensors eliminate the
need for a keyboard in an already
crowded dashboard.

The prototype computer that controls
all of that is currently designed around
three Z80 8-bit microprocessors. It is
anticipated that before production models
become available, the computer will be
based on 16-bit microprocessors such as
the 8086 or 68000. In any case, multiple
microprocessors will be the rule for the
sake of redundancy: in case of one’s fail-
ure, another can step in to keep the system
operational.

Intelligent software

Most of the inner workings we’ve dis-
cussed will be completely invisible to the
operator. Intelligent software is the key to
making The Navigator easy to use with-
out any computer knowledge — and per-
haps without any knowledge of what The
Navigator is.

As already mentioned, operator input
will be done using screen menus. When it
comes to trying to fool the computer by
asking for an intersection of two streets
that don’t meet or an address out of the
range of the actual street, the computer
will pre-check the commands and alert
the operator that those entries are not
legitimate and perhaps that a slip of the

FIG. 3— WITH THE NAVIGATOR, no additional
controls need be added to an already crowded
dashboard. The touch-sensitive screen allows
you to select functions, modes, and more by
simply touching the display.

finger has occurred. Of course, while the
computer can check map data for whether
an address falls within a legitimate range,
it won’t be able to tell you if the location is
a clothing store or an empty lot.

A typical trip

To see how intelligent the software is,
let’s take a hypothetical trip in a rental car
that is equipped with The Navigator of the
future.

You’ve just picked up the keys and an
area-map cartridge from the rental coun-
ter and are ready to leave the parking stall .
You start the car, plug in the film pack,
and the screen lights up and displays a

menu. By placing your finger on the
screen, you select the menu item that asks
for your destination’s address. The screen
changes to a scrolling alphabetical list of
street names contained on the map. A
command line at the bottom of the
screen — also touch operated — offers
fast, slow, and stop scrolling options.
Finding the street name, you stop the
scroll and touch the screen beside the
street name. Next the screen fills with the
numbers zero through nine, which you
press to input the address digits. The
numbers appear at the bottom command
line along with the street name, and stays
there throughout the trip.

Since your present location is already
preprogrammed, the computer plots the
destination on the map and adjusts the
amount of lens zoom required to be able
to display both the present location and
destination. Then the map appears on the
screen. Your location is designated by a
black arrow pointed in the direction that
the car is facing, and the destination
appears as a square.

At this point, you’ll have a choice of
two routing methods. With the aid of the
map on the screen, you can determine
your route as you would with an ordinary
paper map by spotting the major roads or
highways to get you across town. Or,
with the help of the computer, you can
trace a route on the touch-sensitive screen
map with your finger. Then, if you de-
viate from the prescribed route, by taking
a wrong turn for example, the computer
will alert you to it.

JULY 1983

RADIO-ELECTRONICS

FIG. 4— IN THE ELECTRO GYRO-CATOR from Honda, the maps are on overlays that slip over a display
that sits on top of the dashboard.

Your estimated time of arrival and the
distance to your destination also appear
on the command line. As you head out,
the computer obtains readings from a
magnetic compass and the speedometer;
it uses those to update the display every
couple of seconds. If you’re not sure how
to get out of the complex maze of roads
that surrounds most major airports, with a
touch, you can make the computer zoom
in on the airport and show enough detail
for you to see where you’re going.

Traveling through area roadways, you
won’t be tempted to watch the display
rather than the road because the screen
blacks out. Display on/off time will be a
function of speed. After all, you
shouldn’t be studying a video map while
racing down a freeway at 60 mph (indeed
most states outlaw installing a television
in a car so that it can be viewed by the
driver). But if you come to a stop, the
display automatically reappears.

Programming considerations

As can be imagined, the most difficult
part of making a system like The Naviga-
tor commercially viable is the creation
and programming of the film cartridges —
it is expected that those will eventually
cost consumers roughly $30 for a metro-
politan area. Naturally, sophisticated
computers will play a large part in getting
the job done.

Two techniques could be used to gener-
ate the maps. One would be to simply
photograph high-detail conventional
maps. The other is to generate the maps
using computer graphics. The maps could
then be drawn by a graphics plotter and
photographed as before. New technol-
ogy, however, may allow the cost-
effective use of high-resolution
computer-graphics-to-film conversion.
Computers will also be needed to gener-
ate the data that is to be implanted in the
black areas, as well as to bring together all
of the map’s detailed information for in-
clusion on the data-only frames.

Software for the on-board computer
may be designed to be compatible with
CP/M or other popular operating sys-
tems. The advantage to that is that a vehi-
cle owner could preprogram a route into a
cartridge on a home or portable computer
the night before.

The Navigator' s developer predicts
that it could be offered as optional equip-
ment on U.S. automobiles in about five
years, at an estimated cost of about
$1000. It is likely that the most interest in
such a device will be shown by the com-
mercial transportation companies, which
will benefit from routing and other
economies offered by system.

Honda’s system

In Japan, the Honda Motor Company is
already offering a simpler navigation de-
vice, called the Electro Gyro-Cator, on a
limited basis.

In their system, a small control and
display unit sits atop the dashboard. Maps
in this system come in the form of color
translucent overlays that slip in over a
video display (see Fig. 4). At the start of a
trip, you use the console controls to ma-
neuver a screen cursor (a “ + ” symbol)
to the place on the map that corresponds
to your position and the direction you’re
facing.

Then, as your travel, a trip sensor (a
magnetic detection system) measures the
frequency of tire rotation. At the same
time, a directional sensor (shown in Fig.
5) that contains a self-calibrating gyro-
scope detects any turns off the original
course. A small navigational computer
(see Fig. 6) processes the data and gener-
ates the video display. The computer
traces a video line that highlights the path
you’ve taken on the map overlay. There-
fore, you’ll have a display of where you
are on the map and how you got there. If
traffic is at a standstill, you can check the
detailed map overlay for an alternate
route. As with The Navigator, the Electro
Gyro-Cator' s 5- x 6-inch display stays
off until the car comes to a stop . A passen-
ger, however, can keep the display on at
all times if so desired.

Overlays are produced in varying

FIG. 5— THE DIRECTIONAL SENSOR contains a
self-calibrating gyroscope. Its purpose is to
advise the computer of any changes In direc-
tion.

FIG. 6— THE NAVIGATIONAL COMPUTER pro-
cesses data from the sensors and generates the
video display.

scales and are coordinated with adjust-
able scales on the display screen. You can
also map out paths on overlays with a
grease pencil to assist in maneuvering
through new territory. Cost for the Elec-
tro Gyro-Cator, including installation by
Honda, is around $1 100, but the system is
presently not available in the United
States.

Compared to The Navigator' s built-in
map-generation technique, Honda’s
overlays seem cumbersome, especially
when they may need to be changed in the
middle of a trip. But both systems point
toward increased use of computers in
automobiles of the future, and even if
their introduction here is five years or so
away, it is an indication of how far and
how fast consumer applications of com-
puter technology have come. Concepts
that were considered to be too complex
for 20th-century development will likely
be realized even before the end of the
1980’s. Considering that, one must won-
der what the next decade, and the next
century will bring. It might even leave
those in Hollywood breathless. R-E

[sMIWd)

J □

TIMEX/SINCLAIR

Operating System

Build this upgrade for your Timex/Sinclair 1000 and you’ll be
able to store your own system-software modifications in 8K

of nonvolatile RAM.

DESPITE ITS LIMITATIONS, THE TIMEX/

Sinclair WOO microcomputer (previously
sold as the Sinclair ZX81) is a remarkable
machine. It comes complete with an op-
erating system and BASIC interpreter in
8K of ROM; 2K of RAM (the ZX81 came
equipped with only IK); an RF modulator
for black-and-white video output to any
TV, and a cassette interface for program
and data storage. Perhaps the most re-
markable thing about the machine,
however, is its $99.95 price, which is
often discounted to as low as $70, and
may drop even lower in the coming
months.

If you own a Timex/Sinclair 1 000, you
have probably wondered whether it can
be improved. Well, it can. This article
describes one upgrade that you can build
for your machine — an 8K CMOS RAM
board with battery backup. The board can
be used simply to expand the computer’s
system/user memory, or — a more useful

application — the board can be used to
store machine-language subroutines and,
in effect, expand the operating system of
the computer.

The 8K RAM board is designed to be
used with the Timex/Sinclair 1000 com-
puter and a 1 6K RAM pack to form a 32K
system (8K of ROM, 16K of RAM, and
8K of battery-backed-up nonvolatile
memory — see the memory map of Fig 1 ).
In that 32K system, the memory board
would occupy the 8K block from 8K to
16K. That area of memory is a very con-
venient location to store your own
system-software modifications and
machine-language subroutines because it
is transparent to the computer’s operating
system. That means that the memory is
not affected by new, load, or other such
commands that would normally clear the
contents of memory. Even resetting the
computer (turning it off and then on) will
not affect the memory.

PAUL W.W. HUNTER

The CMOS RAM board that we will
describe requires very little power, so it
can use the computer’s + 5-volt regulated
supply. Also, the board requires very lit-
tle drive, so it is unnecessary to buffer the
Z80’s data, address, and control lines.

Possible applications

What can you store in an 8K block of
memory that is transparent to the comput-
er’s operating system? The list is almost
endless, but we’ll give you some ex-
amples.

The Timex/Sinclair BASIC, although

64 K

48 K

32K

16K

SYSTEM VARIABLE "D FILE" CAN APPEArI
ANYWHERE HERE (AND WRITE OVER ANY-
THING YOU TRY TO STORE)

GOOD PLACE FOR DATA STORAGE, BUT
NOT FOR MACHINE CODE-NO OP-CODE
FETCHES CAN BE MADE HERE

THIS AREA IS USED FOR 16K RAM
EXTENSION

TARGET AREA FOR 8K CMOS RAM BOARD.
TRANSPARENT TO OPERATING SYSTEM
AND OP CODE FETCHES ARE POSSIBLE, SO
IT IS A GOOD PLACE TO STORE MACHINE
CODE.

TIMEX/SINCLAIR ROM

oi\

IRY MAP OF the Timex/Sinclair

1000 . The RAM board ignores address line A15,
so additional decoding is necessary if you want
the CMOS RAM to reside at a block of addresses

above 32K.

JULY 1983

RADIO-ELECTRONICS

TABLE 1

TIMEX/SINCLAIR EXPANSION PORT

Description

Signal

Function

Address bus

AO - A15

Outputs memory-and l/O-device addresses

Data bus

DO - D7

Transmits bidirectional data into/out of CPU

MREQ

Identifies any memory-access in progress

IORQ

Identifies any I/O operation in progress

Indicates that the CPU wants to read data

System control

Indicates that the CPU wants to output (write) data

Identifies the op-code fetch cycle of instruction

RFSH

Also used with IORQ to acknowledge interrupt
Synchronizes dynamic-memory refresh

System clock

<)>

3.25 MHz clock (output)

RESET

Resets CPU when pulled low

INT

Interrupt request input

CPU control

NMI

Interrupt request input; cannot be disabled

WAIT

Indicates wait state in machine cycle

HALT

Indicates CPU has executed a HALT instruction

Bus control

BUSRQ

Request to CPU for control

BUSAK

Acknowledgement of release of control by CPU

RAM/ROM select

RAMCS

If pulled high will disable computer’s on board RAM

ROMCS

If pulled high will disable computer’s ROM

Power

+ 9V

Unregulated

+ 5V

Regulated

GROUND

powerful (especially for its 8K size), does
not have read or data commands.
However, machine-code routines can be
written to simulate those commands, and
then those routines can be stored in the
nonvolatile memory and called (by a usr
statement) when needed. That procedure
thereby expands the operating system of
the computer.

Other examples of user-defined
system-routines that might be stored in
the 8K-16K block are: line renumbering,
resequencing, copying, and other editing
routines; custom mathematical or statis-
tical functions; routines to enter, exam-
ine, and edit machine-language pro-
grams; a machine-language disassembly
program; a checksum routine; decimal/
hex/octal conversion routines; other new
BASIC commands; Sinclair code/ASCII
conversion-tables, etc.

Once you have your software well es-
tablished, the memory IC’s can be re-
placed by pin-compatible 2716 or 2732
EPROM’s. Thus you can even make up
your own “game cartridges” that load
almost instantly!

The expansion port

Before we discuss the expansion board
any farther, we will take a look at the port
to which it will be connected. That port,
which is located at the back of the compu-
ter, provides access to all of the lines from
the computer’s Z80 microprocessor. The
lines that are available are listed in Table
1 , and the port’s pinout is shown in Fig. 2.

Peripheral modules like the Timex/
Sinclair 16K RAM pack — as well as the

COMPONENT n7

r +5V UNDERSIDE

SIDE

RAMCS -

- +9V

:i KEYWAY

D0-

> GROUND

D1 -

02-

- CLOCK 0

D6-

- A0

D5-

- A1

D3-

- A2

04-

- A3

Fnt -

- A 1 5

NMI-

- A14

HALT-

- A13

MREQ-

- A12

Torq-

- All

RD-

- A 10

WR -

- A9

BUSAK -

- A8

WAIT -

- A7

BUSRQ-

-A6

RESET”

" A 5

Ml~

“ A1

RFSH-

-- ROMCS

FIG. 2 — THE PINOUT of the Timex/Sinclair 1000
card edge that is available at the port at the back
of the computer.

wide variety of other plug-in units that are
available from various manufacturers —
plug in at the port, as does the CMOS
RAM board. A “piggyback” connector
is included, which allows you to plug the
memory board into the computer, and
then plug other peripherals into the com-
puter via the board.

The signals that are available at the
expansion port are predominantly the Z80
CPU signals. Two additional signals pro-
vided are ramcs and romcs — the chip-
select signals for the onboard RAM and
the system ROM. Having those lines
available allows the user to disable the
internal memory by tying the appropriate
chip-select signal to + 5-volts.

Unfortunately, the connector that is re-
quired for connection to the port is a non-
standard, 46-position (23 per side) card-
edge connector with 0.1 -inch spacing.
However, that really isn’t as bad as it
sounds because the connector can be
fabricated easily enough by cutting the
ends off a standard 50-position card-edge
connector with 0.1 -inch spacing. (The
connector for the computer must have
open ends.) A key should be inserted in
the third position to prevent anything
from being inserted backwards.

The CMOS RAM board

As we said earlier, the board is de-
signed to occupy the 8K block of memory
from 8K-16K. However, it can be easily
“programmed” to occupy other 8K
blocks, simply by changing jumper posi-
tions. (We’ll get to the particulars of that
in a little while.) Of course, you would
probably not want the memory to occupy
the first 8K block (where the computer’s
operating system is contained), but it
could even do that if you wanted it to. The
board could equally well, for example,
replace half of the 16K RAM pack.

The schematic of the memory expan-
sion is shown in Fig. 3. The Z80 mreq
control signal is used to enable the first
half of the 74FS139 dual l-of-4 decoder
(IC5-a), which is used to divide the 32K
of memory into four 8K blocks. The par-
ticular 8K block that the memory board
will occupy is then selected by a jumper
(JU1). (We will discuss how to position
JU 1 as well as all of the other jumpers in a
following section.) The second half of
that 74FS139 decoder (IC5-b) is used to
provide chip-select signals for the 61 16P
2K RAM’s. The Z80 rd signal is used
to enable the outputs of the memory IC’s.

The Hitachi MH6116P (standard or
6116FP-3 low-power version) static
CMOS RAM can be left in a standby
mode when the computer is not in opera-
tion. That is done by backing-up the pow-
er supply with a lithium battery as shown
in Fig 3. With such a back-up, the data
stored in the RAM becomes non-volatile.
(There is also a provision on the board for
an external battery supply other than the
lithium cell.) The 6116P data sheet
specifies that for low-power standby, the
chip-enable pin should be held at a volt-
age at least equal to V cc - 0.2 volt.
Simple NPN-transistor switches (Q2-Q5)
allow passage of the cs signal when the
power supply is connected, but pull the
chip-enable pins to V cc through resistors
R2-R5 when the main power supply is
not present. Transistor Q1 acts as a
voltage-sensitive switch — it switches off
when power from the main supply is not
present which, in turn, switches off tran-
sistors Q2-Q5.

The RAM does not require a full 4- 5-
volt supply in standby mode, and a
lithium cell (3 volts, 150 mAh) works
well. The current drain for a fully pop-
ulated board is less than one microamp.
That means that a single lithium cell

*SEE TEXT
**SEE FIG 9

FIG. 3— SCHEMATIC of the 8K CMOS RAM board. Note that the exact pin connections for the data and
address busses are not shown here — see Fig. 9.

should last for many years. Be sure to
keep the CMOS RAM board plugged into
the microcomputer even when you’re not
using it, and even when the computer is
switched off. Doing that prevents the data
and address lines from floating high —
standby current consumption can in-
crease two orders of magnitude if those
lines go high.

A reset switch is located on the board to
make it unnecessary to unplug the power
supply every time you want to reset the
system. It is recommended that you use
the switch, because if you reset the com-
puter by pulling the plug and then
reinserting it, there is a chance that the
filter capacitor in the power supply will
not have time to discharge. If that hap-
pens, the CPU will not reset when the
power is restored, and you may find that it
will write over all of your nonvolatile
memory.

Construction

We recommend that you use a printed-
circuit board for the CMOS 8K RAM
extension. (The foil pattern for the piggy-
back extender board is shown in Fig. 4,
and the foil patterns for the double-sided
board are shown in Figs. 5 and 6. The
parts-placement diagram is shown in Fig.
7). The author, however, did put together
a prototype CMOS memory board using
wire- wrap techniques, and the circuit
worked well. The usual rules apply —

keep the connections as short as possible;
lay out the circuit in an orderly way in the
smallest possible area without un-
necessary overcrowding; include de-
coupling capacitors at the power-supply
pins of the IC’s; avoid bundling wires
together to prevent crosstalk, etc. With a
wire-wrap board you will notice slight
additional interference on your TV
screen. Using prototype boards with a
ground plane, and then shielding the
boards in a grounded metal case helps a
lot. However, interference is usually less
of a problem with a printed-circuit board,
and such a board will be more reliable in
operation and construction.

If you do use a PC board, solder the
sockets to the board first — use a fine-
tipped low-power (about 27 watts) iron
and take care not to cause solder bridges
between the traces. Make sure the iron is
hot and use a minimum amount of
solder — too much solder may run through
and form a solder bridge on the compo-
nent side of the board.

PARTS LIST

All resistors Va watt, 5%, unless other-
wise specified

R1— 100 ohms
R2-R5 — 1 000 ohms
R6-R10, R1 2—1 0,000 ohms
R1 1—1 00,000 ohms

Capacitors

Cl — 10 |j,F, 16 volts, tantalum
C2-C5 — 0.047 |xF, ceramic disc

Semiconductors

IC1-IC4— HM6116LP-3 150-nS low-
power 2K x 8 CMOS RAM
IC5 — 74LS139 dual 1-of-4 decoder
Q1-Q5 — 2N3904

SI— SPST pushbutton switch (Panason-
ic EVQ-P1R04K or similar)

B1 — 3-volt lithium coin-type battery
(Panasonic BR-2325 or similar)
Miscellaneous: PC board or wire-wrap
board, 1C sockets, card-edge con-
nector, battery holder, etc.

The following are available from Paul
Hunter, 1630 Forest Hills Drive, Oke-
mos, Ml 48864: complete kit, including
a drilled, plated, solder-masked, and
silkscreened PC board; edge con-
nector; piggyback connector; 1C sock-
ets; battery holder; battery; one
HM6116LP-3, and all other com-
ponents, $29.95 plus $1.95 shipping
and handling. (Michigan residents add
4% sales tax.) The PC board alone is
available for $15.00 postpaid. An addi-
tional three HM61 1 6LP-3 CMOS RAM’S
may be purchased with the kit for an
additional $16.

FIG. 4— FOIL PATTERN for the piggy-
back extender board that lets you
use other peripherals with the CMOS
RAM extension. Although it is a
double-sided board, both sides are
the same, so only one pattern is
shown. The installation of this board
is discussed in the text and is shown
in Fig. 8.

JULY 1983 2

RADIO-ELECTRONICS

o o

e o

|< 3-5/8 INCHES >j

FIG. 5— FOIL PATTERN for the component side of the board. Be careful at
the tight spots when you are soldering.

|<- 3-5/8 INCHES >j

FIG. 6 — FOIL PATTERN for the circuit side of the board. There are two
components, SI and the lithium battery B1, that mount on the circuit side.

Solder the card-edge connector in place
as follows: Insert the connector in the
appropriate holes and adjust the stand-off
distance to at least l A inch as shown in
Fig. 8. Make sure the connector is the
same distance off the board at both ends,
and at right angles to it; then solder one

pin at each end. Check the alignment
again, and if you’re satisfied, solder the
remaining pins. Bend the wrap posts in
toward each other as shown. Secure the
second extender board (for piggybacking
other peripherals) between the pins, and
solder the pins to its traces.

Next, solder the resistors, capacitors,
diodes, and transistors in place — refer
back to Fig. 7. Note especially the polar-
ity of the tantalum capacitor, the diodes,
and the transistors. The positive lead of
the tantalum capacitor is nearer to the
bottom of the board. The curved sides of

FIG. 8— SIDE VIEW OF THE CARD-EDGE CON-
NECTOR mounted on the PC board. Note also
how the piggyback extender-board is attached.

all the transistors point to the left side of
the board. Although we will not discuss
the jumpers in great detail at this point, if
you plan to vary your use of the board,
insert wire-wrap pins at the jumper posi-
tions and use wire- wrap wire for the con-
nections.

You should mount the reset switch on
the opposite side (circuit side) of the PC
board where there’s a little more room for
your finger to get at it. Also solder the
lithium-cell holder to the that side of the
board. Hold the battery-holder firmly
against the board when soldering it, and
make sure it’s oriented correctly.

When we continue we’ll finish up the
construction, discuss the available op-
tions, and look at some software you can
store. R-E

JU5 ^CA-

TO OPTIONAL
EXTERNAL SUPPLY

FIG. 7 — COMPONENT-PLACEMENT DIAGRAM for the RAM board. Note the extra pads for connecting
an external battery (other than the lithium battery) for backing up the RAM.

[MUTWcjLjn

£| ui O WE HAVE ALREADY DIS-

■ Cl I L ^ cussed the theory be-
hind how this clock talks. (See the May
1983 issue of Radio-Electronics.) Now
we’ll discuss how to build the clock, and
how to operate it.

Hardware description

Please refer to the block diagram (Fig.
2), and the schematic diagram (Fig. 3) of
the talking clock as we discuss its internal
operation.

The entire clock is controlled by a Z80
microprocessor, IC1 . It keeps track of the
time, reads all the switches, and controls
the speech synthesizer. The control soft-
ware for the processor is stored in a 2516
or 2716 EPROM, IC4, with a capacity of
2K bytes. The microprocessor also uses
two IK x 4 21 14 RAM’s (IC2 and IC3).

The six mode and set switches, S 1-S6,
are connected to the microprocessor
through a Tri-State buffer IC10.

A 74LS139 address decoder, IC9, con-
nected to the microprocessor’s address
and control lines, generates the various
strobe pulses that control reading and
writing from and to the memory, speech
synthesizer, and the switch buffer.

The voice-synthesis processor is the
TMS5220, IC6, which is connected to the
microprocessor bus through a 74LS245
bidirectional octal buffer, IC5. The buf-
fer is needed to isolate the TMS5220irom
the microprocessor data bus.

In operation, the TMS5220 and the
microprocessor operate at different
speeds — the TMS5220 is a very slow de-
vice. Therefore, the microprocessor has
to be slowed down whenever it does a

When you need to know what time it is, this clock tells you — literally.

read or write from or to the VSP. That is
accomplished by using a special line com-
ing out of the voice synthesizer — the
ready line. That line is connected to the
microprocessor’s wait line. When the
microprocessor reads or writes from or to
the VSP, the ready line indicates when
the TMS5220 has finished its data trans-
fer. The VSP will take the microproces-
sor’s wait line low to signal the micro-
processor to temporarily stop and wait
until it (the VSP) has completed its data
transfers. As soon as the data transfer is
complete, the VSP releases the Z80, and
program execution continues.

Speech data for time announcements is
contained in ROM IC7, a Texas In-
struments VM71003 that is pre-

programmed with a clock vocabulary. It
is connected to the TMS5220 by means of
a dedicated interface bus.

The audio output of the voice processor
IC is fed to a simple, passive, low-pass
filter consisting of R9-R1 1 , C5, and C6.
The filter is needed because the speech
waveform coming from the D/A conver-
ter contains some digitizing noise and
must be smoothed out to produce a clean
analog waveform. The filtered waveform
is fed to audio amplifier IC1 1 , an LM386
audio amplifier capable of delivering
over 100 mW — more than enough for
most purposes.

The power supply uses a wall-plug-
type transformer, T1 . The nine- volts AC
from the transformer is rectified by diodes

D1 and D2. The rectified voltage is fil-
tered by capacitors C9 and CIO and then
goes to two 3-terminal regulators, IC12
and IC 13, which regulate it to +5 and
-5 volts, respectively. The clock draws
under 500 mA from the + 5- volt supply,
and under 50 mA from the — 5-volt sup-
ply.

The transformer also supplies the 60-
Hz reference frequency used for the
timekeeping function. A 60-Hz sinewave
is taken from the transformer and rectified
by diode D3 . The signal is then dropped
to TTL levels by a voltage divider made
up from R4 and R5 . That TTL-level sig-
nal is buffered by a Schmitt trigger (IC8-
c) and applied to the non-maskable-
interrupt (NMI) line of the microproces-

JULY 1983

RADIO-ELECTRONICS

60-Hz INTERRUPT

POWER-ON RESET

INTERRUPT

SERVICE

ROUTINE

INITIALIZATION

RETURN TO
MAIN PROGRAM

IS A

SWITCH PRESSED

/ HAS A \
MINUTE TURNED OVER

PERFORM SWITCH
FUNCTION

IF TIME FOR ALARM,
SPEAK ALARM MESSAGE

IF TIME TO
ANNOUM

SAY TIME,

ICE TIME

INCREMENT

16ms COUNTER

IF COUNTER=60
THEN INCREMENT TIME

PRESET TIME & RAM

SPEAK "POWER FAIL"

WAIT FOR SET-SWITCH

FIG. 4— MAIN LOOP IN LOGIC DIAGRAM handles coordination of timekeeping«and speech functions.

(!/6o- second), a count of 60 will indicate
precisely one second. So, every time the
counter reaches 60, the time of day is
incremented by one second. The only ac-
tion performed at the time the interrupt
takes place is the incrementing of the time
counters; resetting of the clock functions
is done in the main loop of the software.

As shown in the flowchart, the primary
function of the main loop is to decide
when to perform certain operations.

Whenever the minute-point is reached,
the software checks to see whether the
alarm is on, and whether the time of day
matches the alarm time. If the alarm is on
and the two times match, then an alarm
message is spoken.

The software also checks to see
whether it’s time to speak the time in the
auto-speak mode. Once it decides that the
time is to be spoken, it composes a phrase
containing the appropriate “hour” and
“minute” words. That phrase is then
spoken by the voice processor.

Another function of the program’s
main loop is to continuously check on
whether one of the pushbutton switches is
pressed. If it finds one of the set switches
pressed, it increments the time, thus
allowing the user to set the time of day. If

sor. Capacitor C3 across the input of the
buffer filters out high-frequency noise
that might give false interrupts.

Software

As mentioned earlier, the entire clock
is software-driven. There are routines to
keep track of time, check whether switch-
es are pressed, compose phrases for
speaking, and control the voice syn-
thesizer to generate speech.

As indicated in the flowchart, Fig. 4,
the microprocessor takes care of all
timekeeping functions, as well as causing
the speech synthesizer to speak words and
phrases.

When power is applied to the clock, the
microprocessor reset line is activated,
and the microprocessor performs a
power-on initialization routine. That
routine presets the time and the alarm to
12:00 AM, as well as initializing some
internal registers. It then alerts you to set
the time by first beeping and then an-
nouncing, ‘ Tower fail. Set the time,"
twice. During initialization the normal
time-speaking function is inhibited.
That’s done to prevent false time-
indications. When the talk button is
pressed, instead of announcing the time,
the clock will tell you to “ set the time."
The normal speaking-function is enabled
only after the time has been set.

The 60-Hz line frequency provides the
time reference for the clock. The 60-Hz
power-line signal is applied to the non-
maskable-interrupt line of the micropro-
cessor. Every time the interrupt occurs,
the microprocessor increments a counter.
Since the interrupts come every 16.67 ms

4-1/2 INCHES >

FIG. 5 — COMPONENT SIDE of clock board. Large pads at right are for connections to switches and
speakers.

the speak time switch is found pressed,
the software composes a phrase contain-
ing the current-time information, and an-
nounces it.

Construction

The talking clock should be built using
a double-sided printed-circuit board with
plated-through holes. A foil pattern for
the component side of the board is shown
in Fig. 5, and one for the “foil” side in
Fig. 6. A professionally made silk-
screened board can be obtained from the
source shown in the Parts List.

PARTS LIST

All resistors V « watt, 5% unless other-
wise noted

R1 , R11 — 10,000 ohms
R2— 330 ohms
R3 — 620 ohms

R4, R8, R9, R12 — 1000 ohms
R5 — 470 ohms
R5 — 180,000 ohms

R7 — 100,000 ohms, PC-mount trimmer
potentiometer
R10-— 100,000 ohms
R13, R14 — 8 x IK SIP (Single In- line
Package) resistor pack

Capacitors

Cl — 330 fxF, 10 volts, electrolytic or tan-
talum

C2 — 0.001 |xF, ceramic disc
C3, Cl 1 , Cl 2 — 2.2 jxF, 10 volts, electro-
lytic or tantalum
C4 — 0.05 fxF, ceramic disc
C5, C7, C13-C15 — 0.1 fiF, ceramic disc
C6— -0.01 }iF, ceramic disc
C8, CIO — 100 jjiF, 16 volts, electrolytic
C9— 680 fxF, 16 volts, electrolytic

Semiconductors

IC1 — Z80 microprocessor
IC2, IC3 — 2114 IK x 4 RAM
IC4 — 2516 or 2716 2K x 8 EPROM, pre-
programmed

IC5 — 74LS245 octal bus transceiver
IC6 — TMS5220 voice-synthesis pro-
cessor

IC7 — VM71003 clock-vocabulary ROM
IC8 — 74LS14 hex inverting Schmitt trig-
ger

IC9 — 74LS139 dual 2/4 decoder
IC10 — 74LS367 hex Tri-State bus driver
IC1 1 — LM386 audio amplifier
IC1 2—7805 5-volt positive regulator
tCI 3 — 7905 5-volt negative regulator
D1-D3 — 1N4001

II — 9 VAC, 600 mA, wall-plug trans-
former

Si -S3 — SPST slide or toggle switch
S4-S6 — SPST N.O. pushbutton switch

Miscellaneous: PC board, speaker, 1C
sockets, heat sink for + 5-volt regulator,
enclosure, wire, solder, etc.

FIG. 6— “FOIL SIDE” of clock board. Double-sided
ordered from supplier indicated in Parts List.

Hand-wired breadboard construction
can also be used if a great deal of care is
taken. The layout should follow the PC-
board design. Use heavy wire for the

board uses plated-through holes and can be

ground and power lines, and make sure
the audio section is away from the other
IC’s to eliminate noise-pickup by the
amplifier.

The following are available from ELEX-
OR, PO Box 246, Morris Plains, NJ
07950: double-sided plated-through
PC board, $12.50; IC4, $7.50; IC6 and
IC7, $25.00; kit of all parts (less enclo-
sure) $69.50. Please add $2.50 for post-
age and handling as well as applicable
state and local sales tax(es).

2 RADIO-ELECTRONICS

When assembling the board refer to the
parts-placement diagram (Fig. 7). Sock-
ets should be used for all IC’s. Install the
sockets, but do not insert the IC’s (except
for the two regulators) until after the ini-
tial checkout. When mounting the diodes
and capacitors, be sure to observe their
polarities. The two SIP (Single /n-line
Package) resistor-networks, R13 and
R14, must have their pin-1 ends oriented
toward the top of the board as shown.
When soldering, use a low-power (about
25 watts) soldering iron and contact the
pads on the board for only a few seconds
at a time to avoid excessive heat buildup.
Excessive heat will lift the pads and thus
ruin the board.

When you’ve finished, check the board
to make sure there are no solder bridges
between IC pins or adjacent traces. The
completed board is shown in Fig. 8.

Final assembly

The assembled circuit board should be
housed in some type of an enclosure. The
enclosure should be large enough to hold
the switches and speaker, as well. The
prototype was housed in a toy-clock case
(with the insides removed). The “alarm
bells” could be mounted on top of such a
case and could contain two pushbutton
switches (S6) connected in parallel to
activate time speaking.

The speak time pushbutton switch
should be mounted in a visible and easily
accessible place like the top or front of the
case, since the switch will be used often.
If the alarm is also to be used frequently,
then the alarm on-off switch should be
mounted in an easily accessible place.
The mode and set switches should be
mounted on the rear of the box to keep
curious fingers from disturbing the time
setting.

The speaker can be any type with an
impedance between four and eight ohms.
The quality of the speech output is highly
dependent on the speaker and its enclo-
sure. Some experimentation can be per-
formed to get the most natural sounding
voice. Best performance will be obtained
when using a speaker with good low-
frequency response. The speaker used in

~ euxoh clk-1

FIG. 8— THE COMPLETED CLOCK BOARD. Note
that IC12 requires a heat sink.

the prototype was 2 3 A inches in diameter
and, in its plastic enclosure, produced
excellent sound.

After the PC board, speaker, and
switches are mounted in the enclosure,
connect the switches, speaker, and trans-
former to the board. Double check all the
connections to make sure they go to the
right places.

Checkout

For this step, the entire clock should be
assembled except for the IC’s.

Before turning on the power double-
check to make sure all the components are
oriented correctly, and check the solder
pads again for cold joints and shorts. Also
make sure that the off-the-board wiring is
correct.

Next, turn on the power and check the
power supplies. Measure the +5- and
- 5-volt supplies to make sure they are
operating correctly.

Now turn off the power and (finally!)
insert the IC’s into their sockets. Make
sure they are oriented correctly. Pin 1 of
all the IC’s should face the top of the
board.

With all the IC’s in place, turn on the
power and listen for sounds coming from
the speaker. If everything is working, you
should hear a beep followed by the words,
“ Power fail. Set the time.” That is the
power-fail message and is spoken
whenever power is first applied to the
clock. If you don’t hear anything, some-
thing is wrong. The first thing to do is turn
off power and re-check the board for cold
solder joints and shorts. Make sure that all
the IC’s are inserted correctly, all the
parts are the correct values, and that the
power supply is working.

Calibration

Calibration of the clock consists of
adjusting the clock frequency of the
TMS5220 (it has a built-in oscillator)
with R7 . It should be 640 kHz (measured
at pin 3 of the IC) for the speech to sound
natural. The adjustment is not very critic-
al, and can easily be made by listening to
the clock’s speech output.

Using the clock

Setting the time is performed by using
the two set time pushbutton switches.
One advances the hours, and the other the
minutes. When the set hours switch is
depressed, the current hour is announced.
(For the set minutes switch it’s the cur-
rent minute.) As the switch is held down,
the time will count up, with each incre-
ment being announced by the clock.
When the desired hour or minute is
reached simply release the switch and the
time will be set.

If the minute/hour set switch is de-
pressed momentarily, the current
minute/hour is announced, but is not
incremented. At the same time, a counter
inside the microprocessor is cleared to

TABLE 1

SI $2 Function

Mode 0 Mode 1

OFF OFF Speak time

every minute
* OFF ON Speak time on

the hour

ON OFF Speak time on

the quarter hour

ON ON Auto-speak

disabled

zero. That counter is used to count time in
seconds, and every time it reaches 60 the
time-count will increment by a minute.
Thus, momentarily depressing the set
switch will synchronize time to the
second.

If the clock is just plugged in without
the time being set, every time the speak
time pushbutton is pressed, the clock will
say, ‘ 'Set the time ’ ’ as a reminder that the
time has not yet been set.

The position of the alarm switch de-
termines whether the time or the alarm is
to be set. If the switch is off, the time of
day will be set. If it’s on, the time the
alarm goes off will be set. The alarm is set
just like the time, except that the alarm
switch must be in the on position.
Remember that whenever the switch is
on, the set switches will set the alarm
time and not the time of day. The current
alarm setting can be heard by throwing
the alarm on/off switch from the off to
the on position. Every time that’s done,
the clock will announce the alarm setting.

To use the alarm, first set the time you
want it to go off, as described above.
Then set the alarm on-off switch to the
on position; that will enable the alarm
circuitry. When the alarm time-setting
time matches the time of day, you’ll hear
the following: “ Good morning. The time
is seven twenty -six AM. Time to get up.”
The time announced is the actual time of
day, and the “good morning” changes to
“good afternoon” or “good evening,”
depending on the time of day.

After using the alarm several times I
found it much more effective and pleasant
than the conventional buzzer. If you are a
heavy sleeper and don’t wake up to turn
off the alarm, it will repeat the alarm
message every minute until it is turned
off. Once the alarm is tripped, it can be
shut off either by pressing the speak
switch, or by setting the alarm switch to
the off position.

Switches SI and S2 are used to select
the auto-speak mode of the clock. In that
mode the time will be announced auto-
matically at predetermined intervals. The
settings are shown in Tabled.

If you choose not to use the auto-speak
mode, you can make the clock tell you the
time simply by pressing the talk button.
If the button is held down, the time will be
announced continuously. R-E

IT SEEMS HARD TO BELIEVE THAT THE

first integrated-circuit operational
amplifiers (op-amps) were introduced
less than twenty years ago. The extremely
low price of IC op-amps, and the almost
unlimited number of applications for
them, have served to make them one of
the mainstays of modern electronic-
circuit design. Indeed, it is difficult to flip
through the pages of any electronics
publication without seeing some refer-
ence to those useful IC’s.

Actually, the term
“op-amp” doesn’t
describe one
integrated-circuit, but
rather is a generic
term for a whole fami-
ly of linear circuits.

There are com-
pensated and un-
compensated types,
single-supply types,
current-differencing
types, BiFET types,
and so on. But one
breed of op-amp,
known as the op-
erational transcon-
ductance amplifier
(OTA) hasn't re-
ceived the amount of
attention that it de-
serves. This article
details both the
theoretical and prac-
tical aspects of the
OTA. By the time you
are done reading it,
you should feel con-
fident enough to at-
tempt your own de-
sign with this interest-
ing type of IC.

One of the earliest
OTA’s was the 3080.

There are now several
others available and,
while they offer sever-
al interesting addi-
tional features, they
essentially obey the
same rules and oper-
ate just like their pred-
ecessor. Hence, de-
signing with the 3080
is emphasized in this
article, but keep in
mind that switching
over to other OTA’s is
easy.

Before considering the internal
makeup of the 3080, we should consider
in general terms just what it is, and what it
can do. In many respects, the 3080 is
much like a common op-amp. It has dif-
ferential inputs. The difference between
the voltages at those two inputs is multi-
plied by a certain gain, and the result is
available at an output pin. Also, the gain

Often ignored by beginners,
operational transconductance
amplifiers are useful and
easy to work with. This
article will give you a good
start toward designing and
building your own projects
using these versatile devices.

THOMAS HENRY

Howto Use
lansconductance
Operational

Amplifiers

can be altered simply by changing the
values of certain resistors. And, finally,
the 3080 needs a bipolar power-supply.

What sets it apart from the common
op-amp, however, is the inclusion of an-
other pin that allows the user to change
the gain (or more properly, the transcon-
ductance) of the amplifier. That control
pin, pin 5, is a current-type input. The
more current, I AB c that flows into the pin,
the greater the IC’s gain. In other words,
that input current varies the transconduct-
ance of the device. In
the January, 1983
issue of Radio-
Electronics, in the
series on analog-
circuit design, the op-
amp was modeled as a
voltage source in
series with an output
resistance. (See Fig. 3
of that article.) The
transconductance
amplifier, on the other
hand, is modeled as a
current source in para-
llel with an output re-
sistance. So, yet an-
other difference be-
tween an OTA and
other op-amps is that
an OTA features a
current output. Speak-
ing very generally,
then, the 3080 is a
current-controlled
amplifier. If you con-
sider the input for
I A bc (the control cur-
rent) to be a program-
ming input, then the
3080 is a programm-
able OTA.

What can such a de-
vice be used for?
There are countless
applications, but
some of the more in-
teresting ones are
voltage-controlled
amplifiers, voltage-
controlled oscillators,
sample and hold cir-
cuits, analog switch-
es, a triangle wave-to-
sinewave converter,
and so on. Several of
those circuits will be
discussed later in this
article.

Internal structure

Now that we know
basically what a 3080
is and what it can do,
we can start to consid-
er its internal makeup.
Unlike some other
integrated circuits,

JULY 1983

RADIO-ELECTRONICS

V L, n II

: |‘ c

v be" *■

- \

)

FIG. 1— THE OPERATION of the transistor
differential-pair amplifier is based on the
relationship of the input voltage to the collector
current

where no specific knowledge of the in-
ternal circuitry is needed to use them, the
unusual nature of the 3080 makes such
knowledge very important.

The usual model used to demonstrate
the internal structure of the 3080 is the
differential-pair amplifier, although there
are a few differences between them. Let’s
take a closer look at such an amplifier.

To understand the operation of the tran-
sistor differential-pair amplifier let’s first
look at the relationship of input voltage to
collector current in a single transistor (see
Fig. 1). That relationship is exponential
and is given by the equation:

l c = |'(e<< v BE-K BT _ 1)

Several physical constants appear in
that equation. The so-called emitter
saturation-current, I prime, depends on
the particular transistor used. Its value
will generally be between 1 and 0.01
picoamperes. Other constants that appear
include K B , the Boltzmann constant, and
q, the charge of a single electron. The
equation can be considerably simplified
by letting V T = K B T/q, where T is the
temperature of the transistor in degrees
Kelvin. The value of V T is then about 26
mV at room temperature. Finally, the - 1
term can be ignored if the transistor is
forward biased. The revised equation is
then:

FIG 2— A SIMPLE transistor differential-pair
amplifier. In analyzing it, it is convenient to as-
sume that the beta of the transistors is very
large.

important; neither 1 1 or 12 can be less than
zero or greater than I Q . At V IN = 0, the
currents both equal I 0 /2.

The curves are, of course, exponential,
but for input voltages of less than 10 mV
or so, the relationship between II and 12,
and V IN , is more or less linear. Therefore,
to keep distortion to an acceptable level in
linear applications, V IN should be held to
10 mV or less. Also, once the input volt-
age exceedes 100 mV, raising V 1N farther
has no additional affect. One of the tran-
sistors will be cut-off, while the other will
be saturated.

A simplified schematic of the 3080 is
shown in Fig. 4. The transistor
differential-pair is quite apparent, as is
the absence of resistors. In their place,
current mirrors are used. In a current mir-
ror, the output current “mirrors” the in-
put current, hence the name. Current mir-
rors CM1 and CM4 are current-sinking
types, while CM2 and CM3 are current-
sourcing types.

Current mirrors CM3 and CM4 mimic
the collector currents of the two transis-
tors of the differential pair. The sum of
those currents is thus presented to the
output. If the two currents are equal, in-
dicating equal potentials at the inverting
and noninverting inputs, the currents bal-
ance and there is no current at the output.
If, however, CM3 sources more than
CM4 can sink, the surplus is made avail-
able at the output. Similarly, if CM4 is
sinking more than CM3 can provide, the
difference must be provided through the
output pin.

Figure 4 also shows a pinout of the
3080. The inverting and non-inverting in-
puts are at pins 2 and 3 respectively; those
are voltage inputs. Pin 6 is the current
output and may source or sink current
depending on the conditions described
above. Pin 5 is the input for the amplifier
control-current, I ABC . Finally, pin 7 is the
positive supply pin and pin 4 is the nega-
tive supply pin.

Some practical design-equations

Having described the internal structure

FIG. 4— SIMPLIFIED SCHEMATIC DIAGRAM of the 3080. The pin-out of the device is also shown here.

, c = |' e VBE/VT

That revised equation is considerably
easier to work with.

Figure 2 shows a transistor differential-
pair amplifier. The input of the amplifier
is at the base of Q1 , while the base of Q2
is grounded. A control current is drawn
from the two tied emitters, and it is that
control current that is used to alter the
gain of the circuit. The output is taken
from the two collectors.

In examining the operation of this
amplifier, it is convenient to assume that
the beta of the transistors is large. In that
case, the emitter currents are approx-
imately equal to the collector current.
Hence, I 0 = 11+12. Using the transistor
equation we previously discussed, and
Ohm’s law, the equations for Ij and I 2 can
be derived. They are:

(1 + e V|n ' Vt )

(1 + e _V|N,v t)

Note the symmetry of those equations;
They must always sum to I Q . That
relationship is shown clearly in Fig. 3.
The asymptotes of that curve are quite

FIG. 3 — THIS PLOT of emitter currents II and 12
shows that their sum is never greater than l Q . In
fact, the sum of II and 12 is a constant and is
equal to l Q .

of the 3080 we can derive some practical
design-equations. The most important is
the so-called general transconductance
equation that relates the output current to
the input voltage and control current. It is:
Iout = 19.2I abc Vin, where Iout an d
I ABC are measured in milliamps and V IN
is measured in volts.

Eventually, we will want to convert
Iout to a voltage, so that the unit will
operate as a voltage amplifier, but for the
moment, note that if V IN is some fixed
input-signal, we can vary the output am-
plitude simply by modulating the control
current I ABC .

Before the foregoing equation can be
put to good use, some practical limits
must be specified. In general I ABC should
always lie between 0.5 /jlA and 0.5 mA
for best results. While it is possible to
increase that upper limit somewhat, it is
best not to do so since the 3080 can go into
thermal runaway.

The inputs at pins 2 and 3 also have
certain limitations that must be respected
for good results. As we previously saw,
the relationship between the input voltage
and the output current is exponential and
once the input reaches 100 mV any further
increase will have no affect on the output
current. Obviously, then, the input must
be limited to less than 100 mV (or 200-
mV peak-to-peak) for any sort of normal
amplifier-response. But for true linear-
response, the input voltage must be lim-
ited even more — a maximum value of 10
mV (20-mV peak-to-peak) is usually
best. There is a trade-off here too, howev-
er, as the lower the input voltage, the
lower the signal-to-noise ratio. Thus,
keeping the inputs at the high end of the
linear range — as close to 10 mV as
possible — is desirable.

Let’s now consider the supply voltage.
The 3080 will work well with any power
supply between ± 2 volts and ± 18 volts.
Those high and low limits are extremes;
best results are obtained with voltages
that are somewhat between those. In
many modem designs, a bipolar 15-volt
supply is used, and that seems about
right.

Before we move on, let’s consider two
other points. First of all, pin 5, the
control-current input, is usually at a
potential that is about one diode drop
above the negative supply- voltage. Thus,
if a bipolar 15-volt supply is used, the
potential at pin 5 is — 14.4 volts. When
calculating resistor values for that input,
be sure to take the negative potential into
account.

Secondly, even though the 3080 is an
uncompensated-type op-amp, compensa-
tion is not usually needed since most ap-
plications use an open-loop design. Com-
pensation is only needed when negative
feedback is introduced. And simplifying
things still farther, the two most common
negative-feedback applications for the
3080, the voltage-controlled lowpass fil-
ter and the sample-and-hold, already use

SIGNAL

INPUT

simple, this circuit works surprisingly well.

capacitors in their designs. Thus no addi-
tional compensation is needed.

Of course, there is much more to work-
ing with the 3080, but that can be picked
up with experience. For now, the rules
we’ve presented are all that you need to
begin designing. Let’s see how to use
them in practice.

Some practical circuits

Figure 5 shows a common 3080
application, a voltage-controlled ampli-
fier, (VCA). That circuit is common
nowadays, and shows up in everything
from noise-reduction units and com-
puterized recording-studio mixing con-
soles to electronic music-synthesizers.
(See the May, 1983 Radio-Electronics
for a discussion of how VCA’s are used in
such synthesizers.) We’ll examine that
circuit first because it involves a very
straightforward application of the design
formulas and constraints we’ve dis-
cussed.

Suppose that our VCA is going to pro-
cess a signal with a peak amplitude of ± 1
volt. As we’ve said, however, the 3080
works best when the input-level is limited
to 10 mV. Hence, resistors R1 and R3 are
used to drop the voltage to that level.
Since R1 is 100 ohms, a similar resistor,
R2 is placed at the other input of the 3080.
In theory the 3080 should now be pro-
perly balanced, and there should be no
DC feedthrough. In practice, however,
offsets can still occur and when those are
modulated by the amplifier severe
“thumps” will result. Therefore, trim-
mer potentiometer R6 is added to the cir-
cuit so that any offsets can be nulled out.
To adjust that trimmer, modulate the con-
trol voltage input rapidly while watching
the output on an oscilloscope. Adjust R6
for minimum DC-feedthrough.

It was seen above that I ABC , fed to pin
5 , should be no greater than 0.5 mA under
most circumstances. Resistor R5 and
transistor Q 1 provide a linear current that

meets that requirement. At the maximum
control-voltage of + 15 volts, Ohm’s law
shows that R5 will conduct a current of
about 0.5 mA. (Remember, pin 5 is at
- 14.4 volts).

A 741 op-amp, IC2 is configured as a
current-to-voltage converter and will pro-
vide a low-impedance output as well. To
calculate the value for R4, we apply the
general transconductance equation. We
know that I ABC is a maximum of 0.5 mA,
and we know that the input voltage is 10
mV (thanks to the attenuator — R1 and
R3). Substituting those numbers into the
transconductance equation yields an out-
put current of 96/jlA. Now using Ohm’s
law, a value for R4 can be calculated. For
unity gain, divide 1 volt (the original peak
input-voltage) by 96/jlA and the result is
10.4K. Pick 10K as the nearest standard
value.

That VCA, while very simple, works
quite well. Perhaps its main fault is the
non-linear response of the control input
when the control voltage is small. A bet-
ter circuit can easily be realized with the
addition of a few parts. Such a circuit is
shown in Fig. 6.

That circuit is actually a linear voltage-
to-current converter. It will produce a
current that is linearly dependent on the
input voltage. In addition, since the tran-
sistor is within the feedback loop, a very
precise response is guaranteed whether
the control voltage is small or large. The
design equation is:

_ V 1N (R1/R2)

where R2IIR3 is the parallel combination
of R2 and R3.

In designing this circuit, you determine

TO 3080,
PIN 5

FIG. 6— FOR BEST RESULTS, this high-
precision current source can be used with the
circuit shown in Fig. 5. Its output is fed to pin 5 of
the 3080.

the desired output-current and then select
appropriate values for R1 and R2. Those
three values are then used in the equation
to determine the value of R3. The circuit,
using the values shown, is set up to output
a maximum current of 0.5 mA for a 15-
volt input. That current is fed to pin 5 of
the 3080. Diode D1 is included to protect
the circuit from large negative input-

JULY 1983

RADIO-ELECTRONICS

voltages.

The VCA just described is actually a
two-quadrant multiplier. It is a multiplier
in the sense that the input signal is multi-
plied by a certain gain; that gain is de-
termined by the control- voltage input.
And it has two-quadrant operation be-
cause the signal is allowed to be bipolar;
the control voltage, though, can only be
positive. For that reason, the graph of the
product of the two inputs, which is the
output of the circuit, can lie only in one or
the other of two quadrants of the four-
quadrant Cartesian plane so familiar to
most of us from elementary algebra. A
four-quadrant multiplier, on the other
hand, allows both the control voltage and
the signal to be bipolar. Thus the output of
that circuit can fall in any of the four
quadrants.

Four-quadrant multiplier

Perhaps one of the most interesting cir-
cuits to come along in quite a while is a
four-quadrant multiplier that uses a single
3080 and a 741 op-amp. Figure 7 shows
such a circuit; its simplicity is quite strik-
ing. Before describing the circuit in de-
tail, a few things should said about four-
quadrant multiplier applications. As
mentioned above, either input of the

+15V 100K

X-TRIM

FIG. 7— A FOUR-QUADRANT MULTIPLIER. This
circuit could be used in a music synthesizer to
create chime and gong effects.

amplifier will accept bipolar signals. The
product of those two signals (divided by a
suitable scaling factor) is available at the
output. But, most important, the polarity
of the output will be correct. For ex-
ample, if two negative signals are multi-
plied, the output will be positive. That, of
course, makes such a circuit quite in-
teresting for, among other things, analog-
computer applications. (Actually the cir-
cuit given here is inverting; that means
that the output will be the opposite of the
true product. That can easily be cor-
rected, if needed, by adding an additional
inverting-stage).

Another place that the circuit is es-

pecially useful is in audio applications.
That’s because it produces sounds that are
quite similar to those produced by a ring
modulator. For example, if two sine-
waves are multiplied by the device, the
output will be a complex signal composed
of the sum and difference frequencies of
the two. Such a signal can be used in
electronic music-synthesis to create gong
and chime effects.

Refer to Fig. 7 now. The two inputs are
labeled “X” and “Y” and are set up to
accept bipolar 5-volt signals (i.e., 10-
volts peak-to-peak). Resistors R8 and R2
form an attenuator and drop the X-input
signal to the desired 10-mV level. Resis-
tors R4 and R6 are in series with the Y
input. To balance the multiplier you apply
a signal to the X input, ground the Y input
(O volts), and then adjust R9 for mini-
mum feedthrough. Then, reverse the
procedure — apply a signal to the Y input,
ground the X input, and adjust R4 for
minimum feedthrough.

The output is converted to a voltage by
IC2, a 741 op-amp. For more demanding
applications, that IC should changed to a
BiFET-type op-amp, such as the LF351.
Note that this stage not only buffers, but
also scales the output suitably — since the
circuit is set up to accept bipolar 5V sig-
nals the output is scaled so that it equals
— V x V y / 5. That puts the output in the
same range as the inputs.

One drawback of this circuit is that

OUTPUT

OFFSET

EVEN TRUK

HARMONIC R6

FIG. 8— IF A TRIANGLEWAVE is fed to the input
of this circuit, the output will be a sinewave of
the same amplitude. The total harmonic distor-
tion will range from 2% to 4%.

only very-low-impedance input sources
can be used. That is easy enough to cor-
rect, though, by buffering the two inputs.
Additionally, the driving sources must be
DC coupled. If those limitations are re-
spected, however, the circuit performs
very well and is far cheaper to build than
any equivalent.

Trianglewave-to-sinewave converter

When we looked at the differential
pair, we said that the input signal must
always be at or below 10 mV for lowest
distortion. A circuit that deliberately vio-
lates that rule is shown in Fig. 8.

In that circuit, which is a triangulwave-
to-sinewave converter, a triangular wave
with a value of 10- volts peak-to-peak is
applied to the input at R4. Resistors R4
and R 1 drop the voltage to about 1 60-mV
peak-to-peak, which is applied to the
3080. Resistor R5 is used to trim the
symmetry, which reduces the even-order
harmonics. Resistors R7 and R3 form the
current source for the 3080, and adjusting
R3 has the effect of rounding or flattening
the output; the result is that the odd har-
monics are reduced. By adjusting R5 and
R3, a very close approximation of a sine-
wave can be obtained. The total harmonic
distortion of the circuit will typically
range from 2% to 4%. Resistor R6 is used
to adjust the output offset.

The output of this circuit will be a sine-
wave with the same amplitude as the input
triangular wave. An important thing to
note about the circuit is that it is non-
reactive — it uses no capacitors or in-
ductors. Thus it will work over a wide
range of frequencies.

As this article has shown, the 3080
operational transconductance amplifier is
not only versatile, but quite easy to work
with. The equations we’ve presented, and
Ohm’s law, are really all it takes to get
circuits using that device up and running.
Obviously there are many refinements
that can be made — correcting for tem-
perature effects, for instance — but they
can be tackled later on when you’ve had
more experience with the device. R-E

c.14

FRED L. YOUNG, SR. and FRED. L. YOUNG, JR.

Keep an eye on the condition of your car’s electrical system with this 3-digit digital voltmeter. Even
if you’re just a beginner in electronics, you can easily assemble it.

MOST CARS THESE DAYS DON’T HAVE

gauges or meters on their dashboards —
they have “idiot lights” instead. They’re
great for telling you when something has
gone wrong, but they do very little to
warn you when something is about to go
wrong. What’s more, even if you are one
of the lucky ones and your car does have
gauges, their accuracy is not the best. A
device with a digital readout would be
much more satisfactory in many cases and
easier to read as well.

The digital voltmeter described here
can be installed in your car (or boat, or
truck) to give you constant and accurate
(to a tenth of a volt) information about the
state of your battery. It is equally useful in
electrically powered vehicles like golf
carts and electric service-trucks (fork-
lifts, baggage carts, etc.). While most of
the latter do have meters, this voltmeter
will prove to be more accurate.

The meter is very simple to build — it
has only three IC’s, three capacitors, five
resistors, three transistors (and, of
course, three LED’s) — and for that rea-
son makes an excellent project for the
electronics novice who wants to “get his
feet wet.” Because it may be your first
project, we’ll go into the details of con-
struction a little more deeply than we
usually do in Radio-Electronics.

How it works

Figure 1 is a schematic of the entire
voltmeter. The LM340T-5 regulator,
IC1 , has an output of five volts, which is
ideal for the other two IC’s in the circuit
and for the LED displays. The input to the
regulator is protected by diodes D1 and
D2, and by a 47 /jlF capacitor, Cl . Those
components minimize positive- or
negative-going voltage spikes that may
be caused by switching inductive devices
like the windshield wipers, air condition-
ing, electric windows, etc., on or off. A
10 /jlF capacitor, C2, at ICl’s output
damps any noise or transients that may
appear on the five-volt output line and
makes the regulator a very stable voltage
source, which is critical for accurate read-
ings.

The heart of the voltmeter circuit is
IC2, a CA3162E dual-slope, dual-speed,
A/D (Analog-to-Digital) converter that
reads the battery voltage and converts it
into a BCD (Binary-Coded Decimal) dig-
ital number. That number appears at pins
2, 1, 15, and 16 of the IC and is fed to pins
7, 1, 2, and 6, respectively, of IC3, a
CA3161E BCD 7-segment decoder/
driver that drives the three FND507
seven-segment LED numeric displays
(DISP1-DISP3).

The CA3161E deserves a little further

attention. It performs several functions
that, in the past, would have required the
circuit to contain a number of additional
components. For one thing, it limits the
current that is drawn by the displays.
Without current-limiting, the LED’s
would tend to overheat and burn out 2nd,
in the past, current-limiting resistors
would have been required to prevent that
from happening; the CA3 1 6 1 E eliminates
the need for them. That IC also allows the
displays to be multiplexed; that means
that only one LED is on at a time —
although they’re switched on and off so
rapidly through driver transistors Q1-Q3
that they all seem to be on sim-
ultaneously. Multiplexing the displays
saves a lot of power, and the total current
needed to operate the voltmeter is 1 60 m A
or less.

The maximum voltage differential
allowed between the input pins on IC2 —
pins 10 and 11 — is 999 mV. Therefore,
resistors R1 and R2, whose values have
the ratio 100:1, are used to form an
attenuation network with a factor of 100.
If 13.8 volts are applied to the attenuator
network, the voltage difference between
the pin 10 (which is grounded) and that at
pin 1 1 (the input pin) will be, according to
Ohm’s law, 136.6 mV. What we want it
to be, though, is 138.0 mV. That differ-

JULY 1983

RADIO-ELECTRONICS

FIG. 1— NOTE THE POINTS MARKED “OPTION’’ at pins 6 and 7 of IC2; they allow the sampling rate of
the converter A/D to be changed. See the text for details.

ence is compensated for by the gain ad-
just potentiometer, R5.

The zero adjust potentiometer, R4, is
used — together with a 0.33 /jlF capacitor,
C3 — to generate the correct internal
ramp-voltage (needed for the dual-slope
A/D conversion process) for IC2. We’ll
discuss the adjustment of both
potentiometers later.

Finally, there are two different conver-
sion rates (the rate at which the A/D con-
verter samples the analog input and
changes it to digital form) available from
IC2. Tying its pin 6 to five volts will
produce a conversion rate of 96 (samples)
per second. That speed, though, will
cause the last digit of the display to be-
come a blur, so we use the other conver-
sion rate — four samples-per-second — by
tying pin 6 to ground. The point at which
the choice of conversion rates is made is
marked “OPTION” in the schematic.

Construction tips

The voltmeter is so easy to build that
the process really needs little description.
Instead, we’ll assume that this is the first
circuit you’ve ever put together, and give
you lots of helpful information. Even if
you’re an experienced constructor, you
may find something of interest here, so
don’t skip this section!

While an etched and drilled circuit
board is available from the source in-
dicated in the Parts List, you may decide
to go all the way and make your own (the
foil pattern is reproduced in Fig. 2). Tech-
niques for making your own PC boards
were discussed in detail in the December
1982-February 1983 issues of Radio-
Electronics. If the board’s foil traces are
naked copper, there is the possibility that
some oxidation may have taken place if
the board was not used immediately, and
the copper may be difficult to solder to. If

that’s the case (or even as a preventative
measure) use a clean dry scouring pad to
wipe the copper side of the board gently
and bring it to a relatively high polish. Do
not try to clean it up using a buffing
wheel! Then wipe it off with a soft cloth.
It should then be as solderable as a board
that’s just been produced.

The choice of a soldering iron is very
important. It should be low power —
about 27 watts — and should be used spar-
ingly. Keep it in contact with the points to
be soldered only long enough to do the
job; if you apply too much heat to a PC
board the foil is apt to separate from the
board. Use as fine a tip as you can get —
that not only keeps heat-buildup down,
but lessens the possibility of your creating
solder blobs and bridges between adja-
cent foil points that were meant to be
isolated. A fine (thin) rosin-core solder
will also help keep your work neat. Use
only as much solder as is needed to
“wet” the connection; don’t make big

blobs.

A final word about soldering: keep the
tip of the iron clean. A clean tip is a
requirement for precision soldering. As
your work progresses, solder will usually
accumulate on the tip of the iron and it is
important that you start soldering with a
clean tip, and that you stop the buildup of
solder on the tip before it gets started. A
damp (not sopping wet) sponge makes a
good tip cleaner. Place it out of the way
on a plate where you can lightly wipe the
tip against it frequently. Wipe the tip
whenever you are about to put the iron
down after using the it, or at intervals if
you are soldering something like a series
of IC pins. And, of course, wipe the tip
well at the end of your work session.

Many components — like IC’s, LED’s,
diodes, transistors, and tantalum or alu-
minum electrolytic capacitors — are pola-
rized. That means that they will work
properly only if they are installed in the
circuit so that the correct pins or leads go
to the appropriate points.

The polarities of diodes and capacitors
are clearly indicated in schematics and
parts-placement diagrams. On diodes,
the cathode end is indicated a band; on
capacitors, the positive lead may be
marked with a dot on the body of the
capacitor, or in another fashion. The Sep-
tember 1982 and November 1982 issues
of Radio-Electronics contained a lot of
valuable information on the various types
of electronic components; you might
want to take a look at them.

Integrated circuits like the ones used in
the voltmeter come in DIP (Dual /n-line
Pin) packages. The pin-1 end of the IC
may be marked with a notch, a dot (usual-
ly placed next to pin 1), or both. Many IC
sockets — which you should use, by the
way, in case you have to remove an IC for
some reason — also have their pin- 1 ends
marked, even though the sockets them-
selves are not polarized. Those markings
help you to remember which way the IC is
to be installed.

Finally, a word of caution about IC’s.
Many of them — including the CA3161E

3-15/16 INCHES >j

FIG. 2— FOIL PATTERN FOR ETCHING the voltmeter PC-board. A ready-to-use board is available from
the supplier indicated in the Parts List.

and CA3 162E — can be damaged by static
electricity. Do not wear clothing made of
synthetic fibers when working with such
devices (although, once they’ve been in-
stalled on the PC board, they’re relatively
safe from harm and you can pretty much
wear what you like). If static electricity is
a problem for you, handle the IC’s under
humid conditions. A good solution to the
problem is to steam up your bathroom by
running the hot water in the shower for a
few minutes and then installing the IC’s in
their sockets in that room while the air is
still damp. That trick is especially useful
in winter.

Construction

BATTERY
(SEE TEXT)

FIG. 3 — NOTE THE RIDGES AT THE TOPS of the display LED’s. The devices must be installed with the
ridges in that position.

A red plastic .filter will make the dis-
plays of the voltmeter easier to read under
difficult lighting conditions. Use a piece
of plastic Vfe-inch thick and a little larger
than the PC board. Drill a hole in each
comer of the PC board, and drill matching
holes in the plastic. To avoid cracking the
fragile material, drill small pilot-holes
first, and then carefully enlarge them. Be
careful not to scratch the plastic. Then set
the plastic aside temporarily and, with the
advice just given in mind, proceed to
“stuff” the PC board.

Use Fig. 3, the parts-placement dia-
gram, to guide you. Install the IC sockets
first, and then the resistors, diodes, and
capacitors. Don’t forget the “OPTION”
jumper, which can be a piece of leftover
resistor lead. Save the larger parts, like
the potentiometers, for last. The 47 /jl F
capacitor, Cl , can be mounted on the foil
side of the board if you wish to conserve
height between the plastic filter and the
voltmeter board.

When you install the LED’s, which can
be soldered directly to the board, be cer-
tain that you mount them with the side
with the ridges at the top (if you look
closely, you’ll be able to see the decimal
point of the display at the lower right).
Solder only two pins, at opposite comers

of each device, first. That will allow you
to reposition the displays easily if you
find that they’re in at an angle.

The five-volt regulator, IC1 , should be
mounted on the foil side of the board as
shown in Fig. 4. Bend the leads carefully
as shown so they arch backwards. The
reason for installing the regulator on the
back of the board is, again, to conserve
height.

Connect about three feet each of red
and black 22-gauge wire to the “IGNI-
TION” and “GROUND” pads of the
board, respectively. That will prevent
confusion later on in connecting the volt-
meter to the vehicle.

Finally, do not install IC1 and IC2 in
their sockets until you have carefully in-
spected the board for poor solder-
connections, solder bridges, proper
component-orientation, and anything
else that you might conceivably have
done wrong ( anyone — even you — can
make a mistake). Then verify that the
supply voltages to the IC sockets are cor-
rect. If you temporarily connect the red
and black wires to a 12-volt-DC source,
you should measure five volts at pin 14 of
the socket for IC2 and at pin 16 of the
socket for IC3 . Pins 7 and 8 , respectively ,

PARTS LIST

All resistors 5%, V \ watt unless
otherwise indicated

R1 — 100,000 ohms
R2 — 1 000 ohms
R3 — 100 ohms

R4 — 50,000 ohms, trimmer potenti-
ometer

R5 — 10,000 ohms, trimmer potenti-
ometer

Capacitors

Cl — 47 fiF, 25 volts, electrolytic
(axial leads)

C2, C4 — 1 0 jjiF, 1 6 volts, tantalum or
electrolytic (axial leads)

C3 — 0.33 fxF, 35 volts, tantalum

Semiconductors

IC1 — LM340T-5 (7805) five-volt reg-
ulator, tab type

IC2 — CA3162E dual-speed, dual-
slope A/D converter
IC3— CA3161E BCD 7-segment
LED decoder/driver
Q1-Q3— 2N2907 or similar PNP
transistor

DISP1-DISP3 — FND507 or FND510
7-segment LED
D1 , D2 — 1 N4002

Miscellaneous: PC board, IC sock-
ets, wire, red plastic filter, mounting
hardware, etc.

The following are available from
Digital World, PO Box 5508, Au-
gusta, GA 30906: PC board only,
$7.50; PC board with schematic,
$8.50; CA3161E and CA3162E,
$12.00; PC board with all three IC’s
and with IC sockets, $20.00; kit of
ail parts (no filter, chassis or sol-
der) $30.00. The prices of the first
two items oniy include postage
and handling costs within the con-
tinental U.S. and Canada. For all
other items add $2.00 within the
continental U.S.; $3.00 all other
U.S., APO, and FPO. Canadians
please use $U.S. postal money
order. Other countries write for
prices and shipping costs. Please
allow 4-6 weeks for delivery.

FIG. 4— THE FIVE-VOLT regulator is mounted on the bottom of the PC board, exactly as shown.

JULY 1983

RADIO-ELECTRONICS

below 1 1 volts (such as when cranking the
starter) indicate trouble!

A possible problem

It is possible that the display-
multiplexing circuit will interfere with
the operation of an AM radio (especially
if the meter and the radio are connected to
the same point) by generating some radio-
frequency interference that will cause the
radio to “whine.”

Some radios are more sensitive to that
problem than others. There are several
solutions to that problem, should it occur.

First, try using a “tie in” point other
than the one used by the radio. Just
remember that it should be active only
when the ignition switch is on.

of those sockets should be at ground
potential; you should measure no voltage
there.

If your voltage readings are correct,
you can disconnect the board from its
temporary power supply and install the
two remaining IC’s. If your measure-
ments differed from those indicated,
recheck the board carefully for errors.
The completed board should look similar
to the one shown in Fig. 5, assuming, of
course, that you used the same types of
capacitors and other parts.

Calibration

Connect a known, accurate, voltage
source to the red and black input wires of
the voltmeter. If you already have an
accurate meter, connect it in parallel with
the one you’re calibrating to act as a dou-
ble check. The calibration voltage should
be between 10 and 16 volts; 13.8 volts is
recommended. Do not attempt to use a
source of less than 10 volts, for it may
result in inaccuracies.

To set the zero adjust trimmer
potentiometer, R4, temporarily ground
pins 10 and 1 1 of IC2 to the ground foil of
the PC board. Then, very carefully adjust
the pot until the display reads “00.0.”
(You’ll need a very fine screwdriver —
and some patience — for this.) You can
then unground the two IC pins.

Adjust the gain adjust trimmer
potentiometer, R5, until the display in-
dicates the exact value of the calibration
voltage being applied. That’s all there is
to it.

Troubleshooting

If the voltmeter did not light up for the
calibration procedure, first make sure that
potentiometer R4 is centered. If there is
still no response, double check your work
once again for solder bridges, unsoldered
connections, components installed in-
correctly, etc. Carefully remove the IC’s
from their sockets and make sure that
none of their pins were bent under.

If the displays are dim, check the emit-
ter and collector leads of transistors
Q1-Q3; you might have mistakenly in-
serted the transistors backwards.

If a digit seems to be trying to display
two numbers at the same time, its driver
transistor may be defective.

If, after you’ve installed the meter, it
doesn’t work, make certain that the red
and black wires are properly connected to
the “tie in” point and to ground, respec-
tively.

Installation

The first step in installing the meter is
to mount the plastic filter in front of it.
That can be done using 3 /4-inch spacers, or
by making spacers using l!/ 2 -inch bolts
and nuts. If you use the latter method,
insert a bolt through the plastic and put a
nut on the reverse side. Then put a second
nut on the bolt, allowing 3 /4-inch of space
between it and the first nut. Do that at all
four corners of the plastic. Next, insert
the bolts through the holes drilled in the
PC board, and secure them with four
more nuts. Securing the plastic at all four
corners gives the assembly greater
strength and minimizes the potential for
the plastic’s cracking from vibration.

The voltmeter does not require a
special cabinet or chassis. It can be
mounted in a recess in the dashboard of
the vehicle and the edges of the mounting
hole covered with a frame, or bezel. For a
touch of class, the displays can be
mounted on a separate board (a duplicate
of the voltmeter board will do quite nice-
ly) and “remoted” from the meter itself.
In that case you’ll need a 14-conductor
ribbon cable to connect the two boards.

The black wire should be securely con-
nected to the vehicle’s chassis ground.
The red wire should go to a point in the
vehicle’s electrical system that is active
only when the ignition switch is turned
on; a good place for that connection is at
the same fuse terminal to which the radio
is connected.

Now that your voltmeter is installed
and working, what voltages should you
expect to read? You’re probably thinking
that the answer is 12 volts. Wrong!
Actually, it should be about 12.6 volts.
When you’re driving, and the battery is
being charged, expect to read about 13.8
volts. Any readings above 17 volts or

FIG. 6— USING RESISTOR R1 as the input allows
you to measure up to 99.9 volts. See the text for
precautions.

You can also try moving the meter
away from the radio (or vice versa).

Finally, you can try shielding the volt-
meter circuit in a metal box. That is usual-
ly very effective.

If you decided to “remote” the display
from the rest of the meter circuit, wrap the
connecting ribbon cable in aluminum
foil, and connect the foil to ground. That
is almost a “must” in applications where
the two units will be separate.

Use with higher voltages

The voltmeter can be used to measure
voltages up to 99.9 volts provided that
two conditions are met.

First, the supply voltage to the board
must be between 8 and 16 volts. Any
lower, and the regulator will not function
properly; any higher and it will quickly
self-destruct.

Second, the end of the 100K resistor
(Rl) connected to D2 should be dis-
connected from that diode, and the volt-
age being measured applied to the circuit
through that resistor. This is shown in
Fig. 6.

A last word of advice: Even though
your new meter will almost certainly be
more accurate than the old indicator you
were using, don’t get rid of the old one!
Keep it in place to monitor the function-
ing of the meter you built, and to act as a
backup just in case something should go
wrong.

If you follow the instructions given
here, you will not only have learned
something about electronics
construction-techniques, but you will
also have built yourself a very useful
measurement instrument. R-E

Using LORAN- C
for Time and

Frequency

Calibration

Here’s a look at the Loran-C navigation system — what it is
and how it works. We will also discover how Loran-C signals
can be used as frequency standards for calibrating
oscillators.

R.W. BURHANS

THE LORAN NAVIGATION SYSTEM Op-
erates on two different frequencies, each
with a different set of characteristics.
Each frequency has its own Loran
designation — Loran-A and Loran-C.
Although Loran-C ’s primary purpose is
for long-distance navigation, it has an-
other important use. Because Loran sta-
tions have to maintain a high level of
precision they can — if used properly —
serve as extremely accurate frequency
standards. In this article we’ll be discuss-
ing how we can use Loran-C signals for
such applications as calibrating a fre-
quency standard or a frequency-counter
timebase.

Before we get into the details of the
Loran-C system, let’s take a brief look at
how Loran-C signals can be used for
calibration purposes. The Loran-C sig-
nals are observed on an oscilloscope that
is externally triggered by a special pulse
generator. (The pulse generator is quite
simple, and we will provide construction
details for it shortly.). The pulse gener-
ator is driven by the frequency standard
you wish to calibrate. (Details for
calibrating a 1-MHz frequency standard
will be given, but other frequency-
standards can also be calibrated using this
technique.) The stability of the frequency
standard can be obtained by determining
the time it takes the display of the Loran-
C signal to drift a given distance across
the screen. Using this technique you can
calibrate a 1 -MHz oscillator to better than
0.001 Hz.

The Loran-C navigation system

Loran-C signals are broadcast on a fre-
quency of 100 kHz with a 20-kHz band-
width (from 90 to 110 kHz). Because of
their low frequency, Loran-C signals tend
to be ground waves — they follow the
earth’s curvature. The signals are usually
very stable because they are not affected
by the ionosphere. But how are they used
for navigation?

Loran signals are sent from a chain
(usually three to five) of stations. One
station in each chain is the master and the
others are slaves. The master station
transmits groups of pulses that are re-
ceived by the slave stations. Each slave
station transmits similar groups of pulses,
and adds a fixed time-delay between the
groups of pulses transmitted by the master
and its own pulse groups. A Loran-C re-
ceiver receives both pulse groups and

calculates the time difference between
them. It is that time difference that is used
to establish a line of position that is used
for navigation.

If (at the receiving end) the time differ-
ence between the received signals were to
equal the original delay added by the
slave station, the receiver would be some-
where along a straight line equidistant
from both the slave and the master
transmitters. If the time difference were
to deviate from that fixed time-delay, the

receiver would be somewhere along a
particular hyperbola. (A hyperbola is a
curve where the difference of the dis-
tances from any point on the curve to two
fixed points is a constant.)

As shown in Fig. 1., a second pair of
transmitters (the same master but a differ-
ent slave) can be used to construct a
second hyperbola. The intersection of the
two hyperbolas is the receiving point. To
be useful for navigation, at least three
Loran stations in a chain must be re-

JULY 1983

RADIO-ELECTRONICS

FIG. 1— AT LEAST THREE Loran stations must be received to be useful for navigation. Each master-
slave pair is used to establish a particular hyperbola of constant time-differences. The intersection of
the hyperbolas gives the receiver location.

ceived. However, for time-and
frequency-calibration applications —
which is what we are interested in — only
one Loran station needs to be received.

One source of more detailed informa-
tion on the Loran-C navigation system, is
the Loran-C Handbook. For information
on its price and availability, write the
Superintendent of Documents, U.S.
Government Printing Office, Washing-
ton D.C. 20402. The book’s stock num-
ber is 050-012-00171-5.

Loran-C receivers

The sophistication of modem Loran-C
receivers is now very high — some will
directly compute your latitude, longi-
tude, range, and bearing. The cost of
those receivers is also high, typically
$5000 for marine systems and $10,000
for airborne receivers. The navigational
precision that can be obtained varies with
the chain’s geometry and distance, but it
can be as good as ± 50 feet when differ-
ential and propagation corrections are
taken into account.

A complete Loran-C navigation re-
ceiver usually consists of the main com-
ponents shown in Fig. 2: an active-
antenna coupler, an RF sensor, a senor
processor, a navigation processor, and
finally a data-display device. The last
three are microprocessor controlled.

The Loran-C signal

Before we can understand how a
Loran-C signal is used by the receivers,
and how we can use it for frequency
calibration, we have to look at its charac-
teristics. A Loran-C signal consists of
pulses. An ideal pulse is shown in Fig. 3.
Each Loran-C transmitter transmits a
series of 8-pulse groups with the pulses
spaced 1 millisecond apart. An extra
(ninth) pulse (sent two milliseconds after
the 8-pulse sequence) is used to identify
the master station. (The master station is
the beginning of the chain’s sequence.)
The sequence is repeated at a certain GRI
(Group Repetition /nterval) that identifies
the chain. Figure 4 shows the relative
amplitudes of the pulse envelopes as re-
ceived from one Loran-C chain (North-
east US: the repetition period is 99,600
/jl s). Each vertical line in the figure
represents one pulse. Note that the rela-
tive amplitudes as well as the time sepa-
rations between the groups will vary de-
pending on the receiver location. (Of
course if that weren’t true, Loran would
not be very useful for navigation.)

An additional characteristic that we
should point out, although it is not shown
in Fig. 4, is that the Loran signals are
phase coded. That allows Loran receivers
to automatically identify master and
secondary stations; to have an automatic

search mode, and to reject multi-hop sky
waves.

Sky waves

One problem encountered when using
Loran-C is that the ground waves are
often contaminated by sky waves.
(Remember — one of the reasons that
Loran can be used for great accuracy is
due to the stability of ground waves.) So
that the signal at the receiver will not be
contaminated by the arrival of sky waves,
a signal with a fast risetime is used. That
allows the pulse to build up to its max-
imum value at the receiver before the sky
waves arrive. Also, the tail of one pulse
should be low in amplitude when com-
pared to the beginning of the next one so
that the trailing sky waves will not con-
taminate the beginning of the next pulse.
The limiting constraint on a signal’s rise-
time is its bandwidth. (For example, a
squarewave has a very fast risetime, but
its bandwidth would be too large to be
used by the Loran system.)

The pulse shape shown in Fig. 3 is used
to reduce the problem of one pulse affect-
ing the beginning of the next — the tails of
the pulses are greatly attenuated (and the
20-kHz bandwidth constraint is still met.)
The third cycle of the pulse (that’s the one
which is tracked by the receiver) will not
be contaminated by sky-wave (or re-
flected) signals.

Because the transmitted signals have a
relatively wide (20-kHz) bandwidth,
ordinary communications receivers can-
not do a good job of detecting Loran-C
pulses, although some receivers with a
12-kHz bandwidth can do a reasonable
job for long-term frequency calibration
(where the local clock is kept running 24
hours a day).

As we mentioned previously, a Loran-
C receiver is designed to detect a point on
the signal (the third cycle) before the
stronger sky waves have a chance to con-
taminate the envelope. That task is not
easy to perform and there is still argument
over the best way to detect the earlier,
weak ground wave at long range when it
has been contaminated with sky waves
(which often have a peak level 20 dB
greater than the ground wave). Because

ZERO

CROSSING

FIG. 3— IDEAL SHAPE of a 100-kHz Loran-C
transmitted pulse. Note how the trailing edge is
attenuated so that the trailing sky waves will not
interfere with the next pulse.

FIG. 2— BLOCK DIAGRAM of a Loran-C navigation receiver.

ENEC>
+ 20
MAS!

IB NANTUCKE

'. R | CARIBOU, ME p*
OdB “ B

LI ..mi,, ilium

CAPE FEAR, DAN,
r NC > + 2f

+10dB 2

111

UN (STATION LOCATION)

)dB (TYPICAL S/N RATIO)

** - - roi nncnn.,o

U H I-abDUU/iO W

START

SEQUENCE

OVER AGAIN

lll|Hip)i H ''lillllM § WITH MASTER

FIG. 4— RELATIVE ENVELOPE AMPLITUDES of a
Note the “extra” pulse that identifies the master.

the sky-wave signals are not stable — they
vary considerably in amplitude and
risetime — large errors will be produced if
the receiver tracks them.

Another problem with Loran receivers
is that any filtering will delay the risetime
of the signal so that, with many receivers,
a point later than the ideal third cycle is
tracked. However, as long as that point is
the same for all signals, strong or weak,
and is chosen to precede the sky wave’s
reaching an appreciable amplitude, then
the receiver can still operate satis-
factorily. Let’s look at how the third cycle
of the Loran-C pulse is detected.

Third-cycle detection

A theoretical way of detecting a point
on the pulse shown in Fig. 3 is to generate
the second derivative of the pulse’s en-
velope shape. The resultant envelope has
a zero crossing at about 35 ps. The prob-
lem in this case is that the envelope gener-
ator (with the differentiators) ends up
with an extremely wide bandwidth — that
adds a lot of noise to the system.

Another way to detect the third cycle is
to produce a delay-and-add circuit. Such
a circuit delays the signal 5 ps (180°) and
then algebraically adds the delayed signal
to the original (with a multiplying con-
stant) to produce a phase reversal at about

TRACKING

FIG. 5— A DELAY-AND-ADD network can be
used to produce a pinched-balloon effect out-
put, which is then used to produce an envelope
with a zero crossing at the third cycle.

Loran-C chain as received in the midwestern US.

the 30- ps point. A simple implementa-
tion of a delay-and-add network — and the
effect it has on the Loran-C signal — is
shown in Fig. 5.

If the output pinched-balloon shape of
the delay-and-add network is fed to a hard
limiter , then the result, as shown in Fig.

5, is a rectangular waveform where the
phase-reversal point (the third-cycle
point) has a gap. All the receiver designer
then has to do is to devise some machine-
language software to track that gap for the
stations of a given chain. That is, of
course, no easy task. But that’s what is
done in the sensor processor of many
Loran-C receivers.

Another problem with Loran reception
and third-cycle detection is that the con-
ductivities of the earth and of seawater are
different. That can cause the group veloc-
ity and the phase velocity of the signal to
differ, producing an envelope-to-cycle
difference (ECD) error up to several mic-
roseconds (depending on the terrain and
the distance). (Some very precise Loran-
C receivers can use that to an advantage.
Precision measurements of the amplitude
and phase of Loran-C signals made while
flying at low altitudes can yield informa-
tion on the ground’s contours.)

Still another problem associated with
Loran-C receivers is the fact that strong
interference on frequencies like 88 kHz or
1 16 kHz can produce errors in the naviga-
tion data. Fixed, tuned traps — that are
designed for particular coverage areas
where there are interferring signals — are
often found in Loran-C receivers.

RF filtering

A signal takes a finite time to pass
through a filter. That time, called a delay,
is a function of the signal’s velocity. The
signal’s velocity is a function of its fre-
quency. (For instance, the signal’s veloc-
ity is lowest at the lower band-edge.)
Thus, a filter can cause EDD (Envelope
Delay Distortion).

The effect that a filter with narrow
skirts has on the received signal is shown
in Fig. 6. Here we have assumed a worst-
case sky wave rising at about 30 ps after
the start of the ground wave, and we have
assumed that the peak amplitude of the
sky wave is 20 dB greater than that of the
ground wave.

The filter delays the Loran ground-
wave signal (the envelope’s zero crossing

occurs at a later time), but coincidentally,
the strong sky-wave signal is also de-
layed. Unfortunately, however, the
ground wave’s third cycle (which we
want to detect) is at - 60 dB . Fortunately,
though, even at the 50- ps point the de-
sired pulse is some 30 dB greater than the
sky-wave contamination.

A - 30-dB contamination of the track-
ing point at 50 ps would result in a small
error in the data. The data will contain
additional error because the results are not
as precise when the fifth cycle (50-ps
point) is tracked instead of the third cycle.
However, as long as the sky-wave con-
tamination is low enough, and the same
point is tracked for all signals, then the
error can be kept down to perhaps 0. 1 ps,
even for a weak signal.

The effect of filtering and AGC in con-
ventional communications receivers de-
stroys most of the information in the
Loran-C signal. However with a receiver
such as the Yaesu FRG7700 in the wide-
band am (12-kHz) mode, it is just possi-
ble to track the fifth cycle (which will be
about the start of the pulse envelope as
observed at the receiver’s line-level out-
put terminal). Noise blankers in com-
munications receivers also destroy the
pulse information because they are in-
herently timed to blank a pulse of the
Loran-C shape and duration.

The envelope detector and simple GRI
generator that we will discuss next are
useful for experimental observations but
are not well suited to precision
navigation-receiver applications. The
minimal equipment required for Loran-C
observation is: a triggered-sweep oscillo-
scope, a frequency standard, a GRI
generator (we’ll discuss one), and a rea-
sonably wideband AM receiver. If you do
not have a suitable receiver available, you
can use the Loran-C front end (or en-
velope detector) that we’ll discuss next.

sky-wave and ground-wave signals, resulting in
an zero crossing at about the fifth cycle.

JULY 1983

RADIO-ELECTRONICS

INPUT FRONT

FIG. 7— THE LORAN-C FRONT END can be used to study Loran signals if a receiver with sufficient
bandwidth is not available.

RF envelope detector

For the experimenter who wishes only
to study Loran-C or to use the signals as a
frequency-calibration source, the en-
velope method (which detects the en-
velope zero-crossing as shown in Fig. 5)
is simple and effective. A schematic of an
envelope detector is shown in Fig. 7. The
active-antenna preamplifier has been de-
scribed previously (see the February,
March, and April 1983 issues of Radio-
Electronics). It uses a 1 -meter whip with
a 150-kHz lowpass filter at the antenna
input. The “receiver” coupler is built as
part of the Loran-C front end (Fig. 7) and
consists of an 80-kHz highpass filter (in-
stead of the 10-kHz filter used with the
previous active-antenna circuits). The
output of that coupler is fed to a network
consisting of a 100-kHz impedance-
matching transformer; to series T-notch
traps tuned to 88 kHz and 115.3 kHz; and
finally to an MCI 350 RF amplifier. The
sequence of matching and filtering at the
input is an impedance step-up to the
MCI 350 RF stage such that there is a net
voltage gain of 10 dB or more between the
active antenna and the RF stage, which
provides an added 60 dB of gain. The RF
stage is operated with a manual control-
voltage for the RF gain (or an external
AGC system could be devised). The
amplifier drives a transformer and a
delay-and-add network. The delayed out-
put and the undelayed (RF-amplifier) out-
put are fed to an MCI 357 FM detector.
There, the hard-limited RF carrier is
mixed or multiplied with the delay signal.
That results in an envelope with the same
amplitude and phase as that from the
delay-and-add network. The zero cross-
ing is adjusted for 40 to 50 /xs, and the
add trimmer potentiometer is adjusted
for a good null at the zero-crossing point.
The actual pinched-balloon effect can be
observed on a scope at pin 11 of the
MC1357.

To align the RF transformers and traps
with the active antenna preamplifier you
can use a signal generator along with a
10-pF coupling capacitor to inject a signal
at the antenna input. (By doing that you
are simulating the response that will be
obtained from the active antenna in the
presence of an electromagnetic field.)
The response at the input (pin 4) of the
MCI 350 should look something like that
shown in Fig. 8, with a peak at about 103
kHz, nulls at 88 kHz and 115.3 kHz, and
fairly wide skirts. The MCI 350 output
transformer is peaked at about 100 kHz
and the delay network is adjusted using an
on-the-air Loran-C signal.

With this front end, the zero crossing
will actually be at about the fourth or fifth
cycle of a strong Loran-C signal. But that
is quite satisfactory. If a Loran-C signal
simulator is available, the network should
be adjusted for a pinched-balloon effect
(or zero crossing) at about 40 /xs.

The output from the limiter/detector
drives a 3-pole 33-kHz lowpass filter (IC3

and its associated components) to gener-
ate a DC envelope that can be observed on
an oscilloscope. The comparators and
flip-flop provide a synchronized 10-/xs
pulse at the envelope’s zero-crossing
point, but it is fairly noisy compared to
observing the envelope at the analog
lowpass-filter output. However, this out-
put pulse for each Loran-C envelope is
useful for further experimenting with
microcomputer tracking-loops (where the
bandwidth of the noise can be narrowed
with memory-aided numerical techniques
in software).

West-coast and foreign experimenters
may wish to align the interference traps at
some other frequencies. It is a good idea
to keep the traps outside the 90 to 1 1 0 kHz
region because they are not high enough
in Q and could attenuate too much of the
desired Loran-C signal. A lot of
retuning — going back and forth over the
adjustments of all of the tuned circuits —
pays off in arriving at a reasonably wide

bandwidth with a sharp phase-reversal at
the delay-and-add network output.

The adjustable RF inductors and
transformers used the circuit shown in
Fig. 7 are normally 455-kHz IF
transformers padded with additional
capacitance to tune them to the 100-kHz
region. The particular transformers in this
experimental circuit are Mouser
42IF303 ’ s , a type sometimes called a 3rd-
IF transformer. Other types will some-
times work, except in the case of the
transformer at the output of the MCI 350.
That’s because the tap on the transformer
is not a true center tap. However, the
loading effect of the 0.01 -mF capacitor at
pin 4 of the MCI 357 makes the output
look like a balanced load for the RF stage.
Some older transformers, from different
manufacturers, may have different wind-
ing phases, so you may have to reverse
the secondary connections to get every-
thing operating properly. The phase of the
smaller output-winding has to be such

PARTS LIST-
ENVELOPE DETECTOR

PARTS LIST—
GRI PULSE SOURCE

Alt resistors Va watt, 5% unless otherwise
specified

R1, R9, R15 — 22 ohms
R2, R3, R4 — 10,000 ohms, trimmer potenti-
ometer

R5, R17, R18, R19, R23, R27— 2000 ohms
R6 — 470 ohms
R7 — 10,000 ohms
R8 — 220 ohms
R10, R16, R22— 1000 ohms
R11, R21--1000 ohms, trimmer potenti-
ometer

R12, R13, R14 — 6800 ohms
R20, R26— 10 megohms
R24, R25— 470,000 ohms
R28 — 2700 ohms

Capacitors

Cl —0.02 ix F, polystyrene
C2— 0.01 ju,F, polystyrene
C3, C8 — 0.0033 fx F, ceramic disc
C4, C5 — 0.01 ix F polystyrene
C6, C7 — 0.005 fx F, polystyrene
C9, CIO, C12, C13, Cl 5, C18, C19, C20,
C23-C26 — 1 fx F, 25 volts, tantalum
Cl 1 , Cl 4— 0.01 fx F, ceramic disc
Cl 6, Cl 7— 0.0068 fxF, polystyrene
C21— 0.001 fxF, ceramic disc
C22— 1 50 pF, ceramic disc
C27— 0.0022 (xF
Semiconductors
IC1— MCI 350 video-IF amplifier
1C2 — MCI 357 sound-IF amplifier and quad-
rature detector

IC3— TL071 JFET-input op-amp
1C4 — LM339 quad comparator
IC5 — 401 3 dual D-type flip-flop
D1, D2— 1N4148
Q1— 2N2222 or similar NPN-type
T1-T5 — 455-kHz IF transformer, Mouser
42IF303 or equivalent
LI, L2— 100-^H RF choke

All resistors Y4-watt, 5% unless otherwise
specified

R1 — 47,000 ohms

R2, R3— 10,000 ohms

Capacitors

Cl, C2— 0.001 fxF

Semiconductors

IC1 — 4518 dual decade divider

IC2 — 1 2-stage binary ripple counter

IC3 — quad 2-input nor gate

D1-D12 — 1N4148

SI -S3 — Hexadecimal thumbwheel switch,
1 6 position BCD, Unimax SF-54 or equiv.

MHz crystal-controlled frequency stan-
dard. There are other methods for produc-
ing GRI pulses, but the three-IC circuit of
Fig. 10 is about as simple as they come.
(You could, for example, use only pro-
grammable decade-dividers. And you
could use something other than a 1 -MHz
standard to drive the GRI generator and
obtain the same results.) The circuit is
programmed in hexadecimal notation for
the GRI intervals as indicated in Table 1 .
That table lists the common designation
for the GRI in 4-digit numbers (/xs/10), as
is done on Loran charts and in United
States Coast Guard data. The pulse gener-
ator that’s shown in Fig. 9 produces a
10- pus pulse that is used to synchronize
your oscilloscope for observing Loran-C
signals.

The programmable GRI-source allows
the experimenter to stop the Loran-C sig-
nals on the scope trace and examine them
in minute detail. That is also the basic

40 60 88 116 140 185

FREQUENCY-kHz

FIG. 8— THE RESPONSE AT THE INPUT to the
RF stage (due to the filters) should look like this.

50,000 to 100,000 pus. We’ll discuss a
simple generator that consists of a 4040
programmable ripple-counter and a dual
decade-divider that is driven from a 1-

(5-12 VOLTS)

that a positive-going envelope is created
at pin 1 of the MC1357 detector IC. The
transformers come with a small 150-pF
built-in capacitor across the main primary
winding, but it can be ignored since it is
very small compared to the 3300-pF capa-
citor required for resonance at 100 kHz.

The LM339 comparator (for the en-
velope pulse signal) generates a reference
voltage from pin 6 of the MCI 357. The
small feedback trimmer potentiometer
across the LM339 reference source is
used to adjust the DC level of the pulse
edge that is fed to the flip-flop. The rea-
son for doing that is that the DC level is
controlled by the MC 1 357 , so that drift in
the lowpass filter DC-level or in the com-
parator reference DC-level is self-
compensating. The envelope lO-jas-pulse
output is intended to drive external logic,
usually at a five- volt level. The power
source for the whole RF front-end should
be from an eight-volt regulated source
(using a regulator such as an LM7808).

GRI pulse source

Practically every Loran-C experimen-
ter needs a GRI generator that is capable
of producing pulse-repetition intervals of

10kHz

100
L- kHz

05 06 07 D8D9 010 Dl.1 012

A a i Ti 4i Aa

8 4 2 1 8 4 2 1 DIODES

f I 1N4148

1MHz INPUT, +V PEAK-T0-PEAK

GRI PULSE OUT

1/44001

OUTPUT BUFFERS

RESET GENERATOR

FIG. 9— THE GRI PULSE GENERATOR is used to stop the Loran signals on the scope trace so that they
can be examined, and their drift measured. The drift indicates the stability of your frequency standard.

continued on page 92

JULY 1983

RADIO-ELECTRONICS

How to Design

Analog Circuits

How lo Use Feedback

MANNY HOROWITZ

This month we turn our attention to an in-depth
look at both positive and negative feedback.

We will discuss both the advantages and
disadvantages of feedback and how to properly
design circuits that use feedback.

We’ve touched upon feedback in
some of our earlier discussions, particu-
larly when we looked at op-amps. In
those discussions we saw that feedback
was important in establishing many cir-
cuit characteristics; this month we’ll look
more closely at that topic. Among the
things we’ll see are the different types of
feedback, how feedback is established in
an audio-amplifier circuit, and how the
presence of feedback affects various cir-
cuit parameters including gain, band-
width, and input and output impedances.
We’ll also see how feedback can cause
circuit instability, a characteristic that is
undesirable in an audio amplifier but vital
in an oscillator.

Before we get too much farther, let’s
clarify two terms. A signal that is fed back
from the output of a circuit to its input in
such a way that the overall gain is reduced
is called negative feedback. If, on the
other hand, the signal is fed back in such a
way that the overall gain is increased, or
so that it causes the circuit to go into
oscillation, it is called positive feedback.

Feedback characteristics

In any circuit that uses feedback, a
portion of the signal at the output is fed
back to the input. The ratio e f /e out , where
e f is the amount of signal that is fed back
and e out is the signal at the output, has
been called p for many years. So as not to
confuse that term with the I C /I B ratio of a
bipolar transistor, which is also identified
by the symbol p, we will use B when
referring to the feedback ratio.

With that convention out of the way,
let’s now look at a basic circuit with feed-
back, such as the one shown in Fig. 1 . In
that circuit, a voltage e s , is applied to the
input. With no feedback, the voltage at
the input to amplifier A, e in , equals e s .
The gain of the overall circuit would then
simply be e out /e in = e out /e s . When feed-
back is added, however, some of e out
appears at the input as e f . Assuming that
the feedback is positive, that is, that the
signals are in phase and thus add, the
input to the amplifier becomes e s + e f .
When feedback is negative, the signals
are 180° out-of-phase and the input to the

amplifier equals e s - e f . Since e f depends
upon e out and B, the gain of the circuit
with feedback is:

where A v is the voltage gain of the ampli-
fier without feedback, or e out /e in , and A F
is the gain of the overall circuit with feed-
back. The denominator of the equation, 1
— BA V , is known as the feedback factor.
When negative feedback is used, the ex-
pression BA V is negative; when positive
feedback is used, that term is positive.

Assuming that the feedback is nega-
tive, and BA V is much larger than 1 , the
gain of the amplifier is just about equal to
1/B . Negative feedback makes the gain of
an amplifier less sensitive to variations in
the circuit’s parameters, such as the sup-
ply voltage. Positive feedback makes the
gain more sensitive to such variations.
We will see why that’s important when
we discuss oscillators.

Because the feedback in this circuit is

FIG. 1 — AN AMPLIFIER with negative voltage
feedback is shown in this block diagram.

applied in series with the input signal, the
input impedance increases over what it
would have been without any feedback;
the amount it increases is directly pro-
portional to the feedback factor. The out-
put impedance, on the other hand, is re-
duced because the feedback signal is
taken from across the load; the amount it
decreases is indirectly proportional to the
feedback factor. We’ll see more about
how input and output impedances are re-
lated to feedback later in this article.

Another effect of negative feedback is
that distortion is reduced and the frequen-
cy response of an audio amplifier is im-
proved. Distortion with feedback is equal
to the distortion without feedback divided
by the feedback factor. High-frequency
response is extended from / OH , the high-
frequency limit without feedback
— BA V ), while the low-frequency re-
sponse is extended from f OL , the low-
frequency limit without feedback, tof OL /
(1 — BA V ). Remember here that since
the feedback is negative the BA V terms
are negative and 1 — ( - B A v ) = 1 +
BAy.

Designing a circuit

When designing an amplifier with
feedback, the first step is to determine the
amount of overall gain that will be re-
quired. Let us say you need a circuit with
a voltage gain of 40 dB, or 100. Assume
that in this application about 20 dB of
negative feedback is necessary around the
circuit to reduce the distortion to about
10% of what it would have been without
feedback. Then the gain of the overall
circuit must be 100 x 10 = lOOOifitisto
be adequate after feedback has been ap-
plied. The circuit shown in Fig. 2 should

FIG. 2— IF THE FORWARD GAIN of this circuit is
to be 100 after 20 dB of negative feedback is
applied, the forward gain before the feedback is
applied must be 1000. The circuit shown here
uses series feedback.

fulfill all the requirements. (That circuit,
minus the feedback loop, was first
covered in the December 1982 issue of
Radio-Electronics; please see that issue
for a more complete discussion of the
circuit). Assume the load, R L , is 10,000
ohms, V cc = 9 volts, and the p of Ql and
Q2 are 100.

Let’s start by determining the values
needed to get an overall gain of 1000
(before feedback is applied). The signal
across the output load should be capable
of an output voltage-swing of close to 9
volts, the voltage of the power supply. To
accomplish that, the value of R6 should
be less than one-fifth of R L . Resistor R6 is
chosen to be 1800 ohms.

The load in the collector circuit is equal
to the resistance of R6 in parallel with R L ,
or about 1500 ohms. Is is actually some-
what less because R F is in parallel with
the 1500 ohms. In this first step of the
design, however, R F can be ignored. For
one thing, we have not yet determined
what the value of R F is. Also, it usually
has only a minor effect on the load resist-
ance as that of R F is very small compared
to that of R L in parallel with R6. So we’ll
ignore R F until after the feedback circuit
has been designed.

The gain of the overall circuit should be
divided between Q 1 and Q2. If the overall
gain without feedback is 1000, we can let
the gain of each stage be about 35 so that
the total gain will be 35 x 35, or 1225,
which, of course, is somewhat more than
1000. As the gain around Q2 is just about
equal to the ratio of the load in the col-
lector circuit to the load in the emitter
circuit (assuming that the load in the emit-
ter circuit is much greater than the AC
resistance of the emitter junction itself),
by rearranging terms we can see that the
value of R5 should equal 1500/35, or
about 43 ohms.

The Q2 circuit presents an impedance
of p x 43 ohms = 100 x 43 = 4300
ohms to the collector of Ql. If a 4300-
ohm resistor is used for R2, the im-
pedance in the collector circuit of Ql is
equal to 4300 ohms in parallel with 4300
ohms, or about 2150 ohms. If Ql is to
provide a gain of 35, the value of R3
should equal 2150/35, or about 61.5
ohms; the closest standard value to that is
56 ohms.

Now, let’s add feedback to the circuit.
Resistor R F and the 56-ohm emitter resis-
tor, R3, are the components that de-
termine the B term in the feedback factor.
If gain is to be reduced by 20 dB and be
equal to 10% of the gain without feed-
back, the gain with feedback, A F , must be
equal to:

A f = 100 = *—

1 - BA V

so that R f must be about 6200 ohms. Note
that since we are again applying negative
feedback, the B A v term here is also nega-
tive and 1 - (- BA V ) = 1 + BA V .

When R F is 6200 ohms, it reduces the
load in the collector of Q2 to a substantial
degree. It was originally calculated to be
at about 1500 ohms. With the additional
6200 ohms across it, the collector load
becomes about 1200 ohms. With the 43
ohms in the emitter of Q2, its forward
gain is now reduced to about 29. To re-
establish a gain of 35 for that circuit, R5
must be changed from 43 ohms to 1200/
35 = 34 ohms. Use a standard 33-ohm
resistor.

In the preceding analysis and example,
the circuit discussed used series feed-
back. The next circuit we’ll discuss uses
parallel feedback; in it, the fed-back sig-
nal is applied in parallel with the input.
That circuit is shown in Fig. 3.

<> **+v cc
> R c

R F < 4.7 K

FIG. 3— PARALLEL FEEDBACK is used in this
circuit.

Let’s assume that we want to use that
circuit in an application where the gain
must be 10. If the p of the transistor is
100, the impedance at the base of the
transistor due to R E , the 47-ohm emitter
resistor, is 4700 ohms. Now assume that
all other impedances at the input of the
transistor are high when compared to the
4700-ohm input impedance. As for the
the output impedance, if R L were 47,000
ohms, the output impedance would be
47,000 ohms in parallel with R c , the 4700
ohm collector resistor, or about 4200
ohms.

Ignoring feedback resistor R F , the volt-
age gain of the circuit is the output im-
pedance divided by the value of R E ; that is
4200/47, or about 90. In order to get a
gain of 10, the feedback factor, 1 +
BA V , must equal 9. If A v = 90, B is just
about equal to 8/90. Because B is equal to
the input resistance divided by R F , 8/90
= 4700/R f . So R f must be about 49,000
ohms. Make the impedance of capacitor
C F very small with respect to R F at the
lowest frequency to be reproduced by the
circuit so that the capacitor does not affect
the feedback.

While the input impedance of a circuit
with series feedback is its impedance
without feedback multiplied by the feed-

JULY 1983

RADIO-ELECTRONICS

back factor, in parallel-feedback circuits
the input impedance without feedback
must be divided by the feedback factor to
determine the input impedance. The out-
put impedance is likewise reduced by that
same feedback factor, just as it was in the
series-feedback circuit. That is because
the feedback signal in both instances is
taken from across the load at the output.

In all of our discussion thus far, the
feedback has been a function of the volt-
age at the output and hence is called volt-
age feedback. The feedback could,
however, be a function of the current at
the output instead. In that case, the signal
is not fed back from across the load but
from across a resistor or other device con-
nected in series with it. That is referred to
as current feedback because the the volt-
age generated across that device depends
upon the current flowing through it as
well as the load. When that configuration
is used, the output impedance increases
with feedback. Input impedance will still
depend upon whether the feedback is in
series with the input signal or in parallel
with it. As always, input impedance in-
creases in circuits where the information
from the output is fed back in series with
the input signal and decreases when that
information is fed back in parallel. Now
we’ll want to take a closer look at current
feedback.

Current feedback

When the current sensed at the output
of a circuit determines the amount of volt-
age fed back to its input, the circuit is
called a current-feedback amplifier. Such
a circuit is shown in Fig. 4. As was the
case with the circuit in Fig. 1, the fed-
back voltage is applied in series with the
input signal.

In Fig. 4, voltage e s is amplified and
appears at the + and - output terminals
of amplifier A. The total output is applied
across the two series-connected resistors,
R l and R s . The output voltage across R L ,
as well as the voltage developed across
R s , varies with the current flowing
through the two resistors. Because the
signal voltage developed across R s de-
pends upon the amount of current flowing
through it, all or a portion of that voltage
can be used to supply the required feed-
back information. Voltage gain of the

FIG. 4— SINCE FEEDBACK IS GENERATED
across a resistor, R F , that is in series with the
load, this amplifier is said to use current feed-
back. That’s because the same current that
flows through the load must flow through that
resistor

overall circuit, with feedback, is:

A F -

1 - BA V ^

( 2 )

The values of resistors R L and R s can
usually be adjusted so that there will be no
need to further reduce the signal fed back
through use of additional B networks. If
that is done, equation 2 can then be sim-
plified by setting B equal to 1 .

Although the circuit in Fig. 3 was
treated as if it used voltage feedback, it
can also be thought of as an amplifier with
current feedback (affecting current rather
than voltage gain) . To see that more clear-
ly , remove R B and Cl from the circuit and
connect R F directly from the collector of
Q1 to the base. The value of R F must be
larger than was found in our original an-
alysis of that circuit so that it can do the
dual job of establishing the feedback and
setting the DC bias of the amplifier. As
collector current divides between R F and
R c , the portion of the current fed back to
the input is 4700/R F . If the current gain of
the amplifier without feedback is A h the
current gain with feedback, A IF , be-
comes:

Note that while one requirement in es-
tablishing a substantial amount of voltage
feedback was to make R F small, its mag-
nitude here has been greatly increased. If
R f is large, voltage gain with feedback is
affected slightly by its presence while
current gain is reduced considerably.

In practical circuits, current feedback
can radically affect voltage gain. Consid-
er the circuit shown in Fig. 5. Here, cur-
rent in the base circuit due to the input
signal voltage is amplified by the transis-
tor. The amplified current flows through
both R c and R E in the transistor’s output
circuit. Voltage e f developed across R E
due to the signal current in the emitter
circuit is subtracted from e s (because the
voltages are 180° out-of-phase with each
other e f bucks e s ) and applied to the base-
emitter circuit of the transistor. Because
e s - e f is less than e s , the gain of the
overall circuit is less with feedback than
without feedback.

Gain may be reduced further by in-
creasing the size of R E . Now a larger
voltage will be developed across that re-
sistor. That larger voltage is subtracted
from e s so that less voltage is applied to
the base-emitter circuit, reducing the gain
further. Hence the gain of the overall cir-
cuit is inversely related to the value of R E .
That was noted earlier when we indicated
that voltage gain of a circuit similar to the
one in Fig. 5, is equal to about R C /R E .
That is true because of the presence of
current feedback.

It was pointed out that for this circuit,

+ Vcc

FIG. 5— IN PRACTICAL CIRCUITS such as this
one, current feedback can greatly affect the cir-
cuit’s voltage gain.

the fed-back voltage is in series with the
input signal voltage. From our discussion
of feedback characteristics, we can con-
clude that the input impedance of that
circuit should increase with the amount of
voltage fed back. That amount depends
upon the value of R E . When basic
amplifiers were discussed, we noted that
the input impedance of that type of circuit
is (3 R e in parallel with R B . That effect of
R e on the input impedance also holds in
circuits were feedback is used.

In order to minimize the affect of R B on
the input impedance, a bootstrapping cir-
cuit may be used. An example of that type
of circuit is shown in Fig. 6. Capacitor Cl
has a large value and it acts as a short
circuit to input signal voltage e s . Without
Cl , the input impedance seen by e s is pR E
+ R in in parallel with R B ; the combina-
tion is in parallel with R x . (As far as the
signal is concerned, V cc and ground are
at the same potential.) By adding Cl to
the circuit, R x and R B are, signal- wise,
across R E while R IN is connected from the
base to the emitter of Q1 . Now the input
impedance of the circuit is equal to the
parallel combination of R B , R x , and R E ,
multiplied by beta. Resistor R IN does not
come into the picture for it is directly
across the low impedance base-emitter
junction; it is negligible when compared
to that impedance. Because R B and R x
have been shifted to be across R E , the
input impedance of the circuit is increased
many times over what it would have been
if Cl were not present.

Feedback in audio circuits

It was pointed out in a previous article

+v cc

FIG. 6— TO MINIMIZE THE EFFECT of R B on in-
put impedance, a bootstrap circuit such as this
one can be used.

that negative feedback is used around
power amplifiers, small-signal audio
amplifiers, op-amps, and so on. Its pri-
mary function is to reduce distortion,
broaden the bandwidth of the amplifier,
and reduce the output impedance. If a
resistor-capacitor network is included in a
feedback loop, the feedback network can
also be designed to alter the frequency-
response characteristics of the circuit.

Let’s take a look at an audio amplifier.
An example of an amplifier that can be
used to reproduce the output from a tape
player is shown in Fig. 7; an approximate
curve that shows the desirable frequency
characteristics of such an amplifier is
shown in Fig. 8. The curve shows that the
amplifier’s output should remain at a
maximum at frequencies below 50 Hz,
should drop at the rate of 6-dB-per-octave
from 50 Hz to 3000 Hz, and then become
level once again at all frequencies above
3000 Hz. To establish that frequency
characteristic, only a series resistor-
capacitor circuit is required in the feed-
back loop. That is shown as C F and R F in
the circuit.

The circuit to accomplish that goal can
be designed through use of an R-C im-
pedance equation and equation 1. The
impedance of the series circuit consisting
of C F and R F is Z F = (R F + j/6.28/C F ) =
(j + 6.28 /C f R f )/ 6.28/C f . (For those un-
familiar with the topic, the impedance of
a resistor and a capacitor in series is equal
to the resistance of the resistor plus the
reactance of the capacitor, where the
capacitive reactance, X c , equals 1/2 ji/C.
However, those two quantities can not
simply be summed, as the voltages across
the components are out of phase. Hence
the introduction of the j operator, where j
= / - 1 . That of course is an imaginary
number and the reactive portion of the
impedance is the imaginary component;
the resistive part of the impedance is
called the real component.) Plugging the
impedance equation into equation 1 , the
voltage gain with feedback is:

1 + A v / R e \

\Re + zj

The portion of the output voltage that
appears across resistor R E is R E /(R E +
Z F ) = B . That is the B that should be used
in the equation. Should R F be much larger
than R e , B simplifies to being equal to
R e /Z f . The entire equation may be sim-
plified farther if the voltage gain is very
large. When A V (R E /Z F ) is much greater
than 1 , the equation simplifies to:

_ Z F j + 2 tt f C F R F

A VF — — =

Re 2 tt f Cp Rf

The above equation is the equation of
the curve shown in Fig. 8. From the
curve, we see that there are two break

FIG. 7— A TAPE PLAYBACK PREAMPLIFIER is
shown here; its simplified frequency-
characteristic curve is shown in Fig. 8.

points, or corner frequencies, where roll-
off begins and ends. The lower break-
point occurs at a frequency such that the
denominator of equation 2 is equal to
zero. The upper break-point occurs at a
frequency such that the numerator of
equation 2 is equal to j 4- 1 .

Let’s first find the frequency where the
denominator is equal to zero. That is, of

FREQUENCY-Hz

FIG. 8— THE SLOPE between the 50- and 3000-
Hz points is 6-dB-per-octave.

course, at / = 0. Thus, at / = 0 rolloff
begins. It will keep rolling off indefinitely
unless there is some frequency where gain
due to feedback begins to rise to com-
pensate for that initial rolloff. That hap-
pens when the numerator in equation 2 is
equal to j + 1, or when /= 1/6.28C F R F .
Since the curve calls for a comer frequen-
cy of 3000 Hz, choose values of R F and
C F that satisfy that condition.

Getting back to the frequency where
rolloff starts, it was determined from our
calculations that for this circuit it begins
at 0 Hz. Actually, the curve calls for it to
start at 50 Hz. That is taken care of by
coupling capacitor Cl. In an actual cir-
cuit, the value of the capacitor would be
selected so that the corner frequency
would fall as close to 50 Hz as possible. In
a more accurate circuit, a resistor would
be placed across Cl so that the corner
frequency could be made precisely 50 Hz.

The curve in Fig. 8 is shown with sharp
points at the comer frequencies. In the
“real world” that never happens — the
changes in the curve are never sharp at the
comer frequencies and the rolloff and the
flat-response sections do not follow the

exact contours shown in the drawing. The
curve in Fig. 8 is only an approximation
of the actual curve required to satisfy the
requirements of the circuit, and is used as
shown here to simplify the design prob-
lem. When designing an actual circuit,
most designers follow that procedure.

Stability

Even when only resistors are used in a
feedback circuit, the feedback is not uni-
form over the entire band. It varies with
the overall gain of the circuit as well as
with the capacitance, inductance, and re-
sistance inherent in the different sections
of the circuit.

To check for stability, plot the frequen-
cy response of the circuit before feedback
is applied. Note the response at the ex-
treme high and low ends of the band. If a
circuit is to be stable, the rolloff, when
feedback is applied, should be less than
12-dB-per-octave. That can be shown
with the help of Fig. 9.

That figure shows the frequency re-
sponse of a circuit. Two feedback lines
have also been plotted — one at — 10 dB
and one at — 20 dB . At the points where
the — 10-dB feedback line crosses the
frequency-response curve, the rolloff is
6-dB-per-octave. At the points where the

— 20-dB feedback line crosses the
frequency-response curve, the rolloff is
12-dB-per-octave. Thus if 10 dB of feed-
back is added to the amplifier, the circuit
is stable, but if 20 dB of feedback is
added, the amplifier will be only margi-
nally stable — it may have a tendency to
oscillate because the line indicating the

— 20-dB feedback level crosses the
frequency-response curve at a point
where the rolloff is 12-dB-per-octave. At
that point, feedback has a tendency to turn
positive.

If the rolloff should exceed 12-dB-per-
octave at the extreme high or low ends of
the band, anything more than 20 dB of
negative feedback at mid-frequency will
turn the circuit into an oscillator.

Oscillators

Getting back to equation 1 , if feedback
is positive, the BA V factor is positive. If
BA V is made equal to +1, the de-
nominator of equation 1 becomes zero
and the gain with feedback becomes in-
finite. A circuit with in-phase positive

FIG. 9— TO CHECK AN AMPLIFIER FOR STABIL-
ITY, first plot its frequency response and then
the feedback. At the points where the curves
intersect, the rolloff should be less than 12-dB-
per-octave to insure stable operation.

JULY 1983

RADIO-ELECTRONICS

FIG. 1 1— THERE ARE MANY different kinds of oscillators. A Colpitts oscillator (a), a Hartley oscillator
(b), and a phase-shift oscillator (c) are shown here.

feedback and a gain of 1 or more after
feedback has been applied will
oscillate — there is an output even though
no input signal is applied.

A conventional feedback arrangement
is shown in Fig. 10. A resonant circuit is
formed by LI and Cl . All feedback oscil-
lators are resonant at a frequency of about
1/2 ji/LC Hz. Oscillation occurs because
of the following sequence of events:
When the supply voltage is applied to the
oscillator circuit, a pulse reaches the L-C
circuit. The L-C circuit turns the pulse
into a waveform at its resonant frequency.
It is coupled from LI to L F and from there
to the base-emitter circuit of the transis-
tor. That signal is amplified by the tran-
sistor and applied to the resonant circuit.
If the signal across LI and L F is in the
proper relative phase, it keeps on being
fed back and amplified until the overall
circuit remains in oscillation.

Oscillators have many shapes and
forms — three are shown in Fig. 11. The
oscillator shown in Fig. 1 1-a is known as
a Colpitts oscillator. When calculating its
resonant frequency, use C1C2/(C1 +
C2) for the total capacitance of the L-C
circuit. Another popular oscillator is the
Hartley, shown in Fig. 1 1-b; it s resonant
frequency is simply 1/2 ji/LICT. A feed-
back oscillator circuit using only resistors
and capacitors is shown in Fig. 11-c. It
oscillates because the transistor shifts the
phase of the signal 1 80° from the base to
the collector. Each of the R-C networks in
the circuit is designed to shift the phase
60° at the frequency of oscillation, for a
total of 1 80°. The appropriate values of R
and C_for each network is found from / =
l/(2/3jtRC); that equation allows for the
60° phase shift required by the design.

+v cc

FIG. 10— A CONVENTIONAL FEEDBACK
OSCILLATOR. The values of LI and Cl de-
termines the frequency of oscillation.

Adding the phase shift due to the transis-
tor and the phase shift due to the R-C
circuits, the overall phase shift from the
input to the output is 360°. Signal from
the output is fed back to the base in a
positive feedback arrangement (due to the
360° phase shift), to reinforce the signal
present at the base. That signal at the base

was initiated by a random pulse when
power was applied to the circuit, it was
amplified, the phase shifted 360°, and fed
back. The oscillator frequency will be
about:

f = J 4(R1) R c + 6 (R1) 2

2 it (Cl)

if R b is considerably larger than Rl.
Should Rl be omitted from the base cir-
cuit, the input resistance of the base cir-
cuit, when combined in parallel with R B ,
must be chosen so that the combination is
equal to R2 or R3 (note that Rl , R2, and
R3 are all equal).

Oscillators can be built around op-
amps. The output of the circuit shown in
Fig. 12 is a square wave; let’s see why.
Negative feedback is established through
R F1 , while there is positive feedback
through R F2 . For that circuit, as well as
for circuits described below, assume that
the positive saturation voltage at the out-
put of the op-amp is + V cc and that the
negative saturation voltage at the output is
— Vco The voltage at the non-inverting
input depends upon the voltage at the
output. It is positive when the saturation
voltage is at + V cc , and negative when it
is at -V cc -

Assume the oscillation starts when the
output is at + V C c- At that time, Cl gets
charged to a positive level through R F1 .

When that voltage exceeds the positive
voltage at the non-inverting input, volt-
age at the output drops to — V C c- When
that happens, the voltage across Cl be-
gins to drop and become negative because
its charging voltage is now being supplied
by the negative voltage at the output of the
op-amp. Once it drops to below the volt-
age at the non-inverting input, the voltage
at the output returns to + V C c- The pro-
cess keeps repeating itself. Con-
sequently, the output is a squarewave.
The frequency of oscillation is 1/2R F1 C,
provided that B = 0.462. Since B =
R1/(R1 + R F2 ), that condition will hold
true if R F2 is made equal to 1 . 16R1 .

A sawtooth generator is composed of

FIG. 12— OP-AMPS are commonly found in
oscillator circuits. The output of this circuit is a
squarewave.

continued on page 94

Switch to BambiT

Electronically

Bambi Electronic Video Switch
makes switching of your VCRA
Pay TV Decoders, Cable TV, Vic
Discs, Video Games, Closed Ci

• Weight

Bambi's front panel was designed with the
user in mind. Computer styled construction,
with soft-touch keyboard (rated for over 10
million operations), arranged in matrix form
allows easy input/output selection without
refering to charts. Functions selected through
the keyboard are immediately displayed on
the 1 8 LED status indicators.

Check the quality of Bbmbi against that of
much higher priced competition. All solid
state electronic switching provides low atten
uation (3dB), wide frequency response (40-
890 MHz), and excellent isolation between
signal sources (each I/O section individually
sheilded for 65dB min. isolation).

SWD-1 VIDEO CONVERTER

FOR CABLE TV

The SWD-1 Video Converter is uti-
lized on cable TV systems to re-
move the KHz s signal from a
distorted video (channel 3 in/
out) and also pass thru the
normal undistorted/detected
audio signal. Rocker switch
vB. selects operating mode to remove KHz’s

distortion from the video or pass all other chan-
nets normally. Simple to assemble — less than 30
minutes. Pre-tuned. Input/output Channel 3. Impedance
75 ohms. 1 1 7VAC.

SWD-1 Video Converter Kit $69.95

0-35dB VARIABLE GAIN

RF AMPLIFIER

USES TWO REVOLUTIONARY
NEW HYBRID

BROADBAND AMPLIFIER ICs

Works on all RF Signals from 40-900MHz

EXCELLENT FOR USE WITH:

CV 2>Jr • All Antenna Systems

• Voice Communications

VJ**-- ALL-2VG

amplifier • MATV Systems
^ \ # CCTV Systems

• Video RF Line Amplifiers

• Frequency Counters
feed • Oscilloscopes

supply • FM Broadcasts

Now you can use one TV/FM Antenna to cover all close and
distant stations without experiencing overloading problems.
Ideal for outdoor and indoor use. I/O impedance is 75 ohms.
Power Supply is separate coax feed system which allows
amplifier to be located anywhere in cable run. Power Supply
has knob to control varible gain, LED power on indicator and
on/off switch.

ALL-2VG Wired and Tested $49.95

Our New SIVA 14.5dB GAIN, 14 ELEMENT
CORNER REFLECTOR YAGI ANTENNA

STVA-3 Yagi Antenna, 14.5dB Gain, Selectable 75 or 300 ohm

Channel 60-80 $19.95

STVA-4 Yagi Antenna, 14.5dB Gain, Selectable 75 or 300 ohm

Channel 44-52 $19.95

RG-59/U 75 ohm Low Loss Coax Cable. . . $.12p/ft F-59 Coax Connector. . . $ .39 ea.

MT-1 Special UHF 75-300 ohm Matching Transformer $1.45 ea.

SPECIAL

PACKAGE

OFFER

. MAE-2, KSDC-KIT and $14

r KSPS-1 A for Only I* 1

Regular price if ordered separately $82.85

— CO-AX CABLES ARE NOT INCLUDED

★ PWD

FOR DETAILS SEE
OUR PAST ADS

FREE

Bambi

Poster

with

any

purchase

Assembly

Time

Approximately
5 Minutes.

• Not A Kit
• 1 .9-2.5 GHz • 38V 2 " Long

i iw»| n || • 23dB Average Gain • Commercial Grade

l* Jrnlj • D' e Cast Waterproof Housing with 4V8" x 2 V 2 "

Area for Electronics

• Includes P.C. Probe, F-61 Connector and Mounting Hardware

MAE-2 32 Element YAGI Antenna $23.95

Kato Sons Regulated Varible DC Power Supply

For use with KSDC-KIT 1.9 - 2.5GHz Down Converter. Completely assembled
with Attractive Cabinet, TV/Converter Mode Switch, Frequency Control and
LED Indicator.

Model KSPS-1 A Assembled Power Supply $23.95

^^^nVIODU LATOR

Not a Game Type Modulator

- f^S| The MPS_1 Kit converts Video/ Audio
I signals to a crystal controlled RF

output for TV Channels 3 and 4.
The MPS-1 Modulator's adjust-
:^rr-1 ^ ■- able inputs are designed to match
£ a j| jy Cameras and VCRs and features a ,
voltage regulated power supply, power switch
and LED indicator. No Tuning Required. Operates
on 1 1 7VAC. Ideal for use with our new Debbie
CCTV-1 and revised Bambi BEVS-1 S.

MPS-1 Modulator Kit. ........ $39.95

SEE PACKAGE OFFER BELOW FOR ANTENNA,
DOWN CONVERTER, POWER SUPPLY, & RF AMP.

Kato Sons' Down Converter Kit *1.9 - 2.5GHz*

Designed for Simple Simon by former Japanese CQ Amateur Magazine's UHF
Editor/Engineer. Unit utilizes new ingenious Printed Circuit Probe for maximum
gain. Circuit board fits inside MAE-2 antenna housing. Requires mechanical
assembly only. All electronics are pre-soldered and pre-tested. Usable up to
approximately 15 miles

Model KSDC-KIT 1.9 - 2.5GHz Down Converter Kit . . , $34.95

Kato Sons RF Amplifier *22dB Gain*

High quality 2 stage low noise RF Amplifier for 1 .9 to 2.5GHz. Unit requires aprox-
imately 10 minutes assembly. Fits in same housing with down converter. Covers
distances of up to 30 miles.

Model KSRF-2 RF Amplifier $23.95

BE SECURE WITH BAMBI!

Bambi Now Provides Home/Industrial
Security With The New ...

Automatic Sequential Scanning BEVS-1 S

That's right! In addition to Bambi’s regular features listed
above, we have added Autoscanning with a controlled 1-10
second Varible Delay for up to six input security cameras.

The BEVS-1 S allows simultaneous recording on a VCR while observing activity
on the monitor. Manual lock-on of any one of six inputs can be accomplished at
any time. The BEVS-1 S coupled with our new Debbie CCTV-1 listed below
makes an excellent security system for your Home or Business.

BEVS-1 S Sequential Scanning Electronic Video Switch. . . $199.95

You Should Have Debbie’s™ Quality!

ORDER ALL THREE ITEMS

AE-2, KSDC-KIT and $7V|95

5PS-1A for Only 1*1

SPECIAL

PACKAGE

OFFER

ORDER ALL FOUR ITEMS

MAE-2, KSDC-KIT, KSPS-1 A $Q A 95

' and KSRF-2 for Only 51*1

Regular price if ordered separately $106.80

— CO-AX CABLES ARE NOT INCLUDED —

SIMPLE SIMON ELECTRONIC KITS,™ Inc.

3871 S. Valley View, Suite 12, Dept. R, Las Vegas, NV 89103

nkd 6 ITCM? |n Nevada Call: 702-871-2892

QUANTITY DISCOUNTS 7QO £1

Outside Nevada Call: I "OUU" # Ofc" W # IO

Outside Nevada Call:

WRITE FOR OUR CATALOG OF
ADDITIONAL CCTV ACCESSORIES

Available by Mail Order Only
Send Check* or Money Order. Minimum
Order: $16.95. Add 10% Shipping and
Handling on orders under $40.00. For
orders over $40.00, add 5%. Minimum
Shipping and Handling $2.00. Cat. $1.00
— VISA and Mastercard Acceptable —
‘Check orders will be held 30 days before shipping.

Debbie

CCTV-1

CLOSED

CIRCUIT

TELEVISION

CAMERA

Excellent For Use In Home or Business Security
Systems, Monitoring Production Lines, Childrens
Play Areas, Etc.

Features:

• 2/3" Electrostatic Focusing Vidicon Tube

• EIA 525 Line, 60 Fields Per Sec. Scanning System

• 600 Line at Center Horizontal Resolution

• 1 Footcandle Minimum Illumination

• 1 0,000 to 1 Automatic Light Control Range

• 1 .OVpp Composite, Negative Sync, 75 Ohm Video Output

• 40dB Signal to Noise Ratio

• Standard "C" Lens Mount

• 1 1 0V ±1 0%, 50-60Hz, 9 Watts

Debbie CCTV-1 Requires C-Mount Lens $159.95

16mm, FI. 6 Hi-Resolution Lens w/Cap 19.95

Mounting Bracket Flexible, Locking, 360° Gooseneck for use in
ceiling or wall mounting 12.95

NOTE: When using the Debbie CCTV-1 with Bambi BEVS-1 S, an RF Modulator such
as our Model MPS-1 is required.

MODEL IC-1 INFRARED CONVERTER

Adapts to any video camera. Reduces energy costs for night view-
ing by 60%. Video tape in the dark without being detected.
Excellent for • Factory Grounds Security • Home Surveillance.

Write for Details.

JULY 1983

RADIO-ELECTRONICS

NEW IDEAS

Low-distortion audio limiter

SHORTWAVE LISTENING AND DXlNG IS,

without a doubt, an enjoyable hobby.
However, it does pose a hazard to your
ears — or to your peace of mind — because
of the annoying loud-volume pops and
blasts you’re sure to hear from your com-
munications receiver. Although the AGC
(Automatic Gain-Control) circuits in
communications receivers are supposed
to take care of those sudden changes in
volume, they never seem to do the job
well enough. Those of you who wear
headphones are especially vulnerable to
the annoyance. What’s especially annoy-
ing then is that you’re probably wearing
the headphones not for your own benefit,
but for the benefit of those around you.

I tried several ways to reduce the prob-
lem (for example, using FET’s as at-
tenuators) but I was unhappy because I
was always trading one problem off for
another: distortion. But I finally came up
with a design that does what I want — it
attenuates the blasts from my com-
munications receiver while causing no
noticeable distortion.

The circuit of the audio limiter is
shown in Fig. 1. The level at which it
comes into action can be set with the
limit level trimmer potentiometer.
When that level is exceeded, the output
from the limiter-detector half of the
op-amp (which is used as a comparator)
causes the LED to light. The light from
the LED causes the resistance of the
photoresistor to decrease rapidly. That in
turn causes the gain of the limiter half of
the op-amp to decrease. When the signal
drops below the desired limiting level the
LED turns off, the resistance of the photo-
resistor increases, and the gain of the
limiter op-amp returns to its normal
level — that set by the combination of re-
sistors R1 and R2. A dual-polarity power
supply (±12 volts is desirable) is, of
course, needed for the op-amp.

output

. Cro speaker or

(From receiver's headphones)

The circuit is very easy to build, and
since the construction method is not cri-
tical, use the one you prefer. You might
even want to mount the circuit inside your
receiver. One important construction
note, however, is that the photoresistor
and LED should be encased facing each
other in a light-tight enclosure.

The parts that you use are not critical
either. One note here however is that the
(cadmium sulfide, or CdS) photoresistive
cell is most sensitive to light with a
wavelength of about 5000 angstroms (or,
approximately, green light). Therefore,
you may want to use a green LED for best
response.

Perhaps the best feature of the audio-
limiter circuit is that it can be used with
any receiver, whether it’s a tube-type
shortwave receiver or a new solid-state
scanner. Your ears will thank you. —
Daniel Ulmer

NEW IDEAS

This column is devoted to new ideas, cir-
cuits, device applications, construction tech-
niques, helpful hints, etc.

All published entries, upon publication, will
earn $25. In addition, Panavise will donate
their model 333 — The Rapid Assembly Circuit
Board Holder, having a retail price of $39.95. It
features an eight-position rotating adjust-
ment, indexing at 45-degree increments, and
six positive lock positions in the vertical plane,
giving you a full ten-inch height adjustment for
comfortable working.

I agree to the above terms, and grant
Radio-Electronics Magazine the right to
publish my idea and to subsequently repub-
lish my idea in collections or compilations of
reprints of similar articles. I declare that the
attached idea is my own original material and
that its publication does not violate any other
copyright. I also declare that this material has
not been previously published.

Title of Idea

Signature

Print Name

Date

Street

City State Zip

Mail your idea along with this coupon

to: New Ideas Radio-Electronics,
200 Park Ave. South,
New York, NY 10003

No wonder they call it the SUPERFONE!

At Last— a Cordless Phone
with TWICE the Range, Sound
Fidelity to Rival Phones with
Cords, and a Privacy Code
System— All This in a Phone
Less Than an Inch Thick!

The Super Fone is less than T' thick. The base unit has a built-in speaker phone,
a fully independent intercom and is 110 volt-220 volt switchable.

Until now, cordless phones have
given you wonderful convenience. But
they’ve had two problems:

1. The range is limited to 600 to 700
feet.

2. Some of them sound as though
you’re talking inside a barrel.

As cordless phones have become
enormously popular, another problem
has arisen: two people, living near each
other, can have the same channel. Not
only is there line confusion, but someone
else can literally make a long distance call
on your phone.

No more. Never again.

Range: 1500 Feet OR MORE!

The SuperFone 650 uses state-of-
the-art electronics to bring you the
ultimate cordless phone. Sound quality is
superb — and it stays superb, 1 500 feet or
more from the base station. That’s more
than twice the distance of standard
cordless phones.

Only SuperFone 650 has a secret
code system to prevent interference and
false operation of the phone. You choose
from 512 possible “code” combinations.
Both the base unit and the phone are
locked onto that code, which you can
change when you want to.

No other phone can interfere. No
other unit can share the signal. No one
else can hear or speak on your carrier-
wave.

Enormous Range

We say the SuperFone 650 has a
range of 1500 feet.

Notice we didn’t say “up to” or “as far
as” 1500 feet. There’s no hedging,
because this seems to be the minimum,
not the maximum range.

Users report 1800 and 2000 feet.
That’s nearly half a mile. SuperFone 650 is
a radiophone, not a toy, and that’s why its
signal doesn’t break up or start hissing or
crackling when you get half a block away.

You can tell when you heft it. It’s a
Little Giant. You can feel the power inside.
What a marvel of electronic engineering it
is! And it’s tough, too. It fits into your shirt
pocket, and you can bounce it around all
day without damaging it.

Speakerphone, Intercom —
Everything!

SuperFone 650 is The Everything
Phone. Anything any phone can do, it can
do.

First, the base station is a speaker
phone. Touch a button and you can have
a hands-free conference conversation in
the room in which the base station sits.

Next, it’s an intercom. You can page
the handset from the base unit and have a
private conversation. You have a true
wireless intercom, not just a signal.

Third, you have a privacy button.
Push that button and you’ll still be able to
hear anything the other party says, but he
or she won’t be able to hear you until you
take the button off “hold.”

Fourth, you have an automatic redial.
Touch the key and the SuperFone will
redial the last complete number.

What else? A security switch which
makes it impossible for anyone to call out
on the remote phone, without changing
the ability to receive calls. A volume
control for the speaker on the base unit. A
call button to page the base from the
cordless phone. THIS PHONE HAS
EVERYTHING!

30-Second Installation

Plug your SuperFone 650 into any
wall AC outlet. Push its standard modular
terminal into the telephone plug. You’re in
business.

Every component is heavy-duty,
from the built-in condenser microphone
(with automatic gain control) to the LED
indicator lights. This phone is designed for
hard use.

The SuperFone 650 is yours for
$249.95. If you want the SuperAntenna
with it, giving you a range of a mile — or
even more — you can have both for
$319.95. (Or you can get the Super-
Antenna alone for $79.95.)

We Absolutely Guarantee!

Use the SuperFone 650 (or any
electronic instrument you acquire from
us) for up to 30 days. If for any reason you
decide not to keep it, return it for a 100%
refund.

The SuperFone 650 — $249.95
The SuperAntenna — $79.95
BOTH Phone and Antenna — $319.95
Adapter for Multi-Line phone — $39.95

Add $4.50 per total order for shipping.

New!

MULTILINE ADAPTER

FOR BUSINESS PHONES

If you have several lines, you can
plug them into your SuperFone with this
single adapter.

The adapter costs $39.95. Nothing
else is required to attach multi-line
phones to one SuperFone 650.

TRIPLE THE RANGE
OF ANY CORDLESS PHONE!

The StiperAntenna will give your
cordless phone, regardless of make or
model, three times the range it has now.

If the range is 700 feet, it’ll leap to
over 2,000. If it’s 1500 feet, it could be as
far as one mile!

Easy to install. Only $79.95
complete. Add $4.50 for shipping.

For instant service, if you have a VISA
or MasterCard, call toll-free 24 hours
a day, seven days a week:

1 - 800 - 824-7888

Ask for Operator 551.

(in California: 1-800-852-7777)

The SuperFone 650, SuperAntenna, and
Multi-Line Adapter are more electronic
marvels from

new horizons

Dept. RE-7 , 1 Penn Plaza, Suite 100
New York, NY 10119

JULY 1983

RADIO-ELECTRONICS

HOBBY CORNER

Reducing battery drain

EARL ‘‘DOC’’ SAVAGE, K4SDS, HOBBY EDITOR

THE FIRST LETTER THAT WE’LL LOOK AT

this month is from Ken Alexander in Ten-
nessee. He built and installed a security
alarm system in his car. The alarm
doesn’t draw any current until it is acti-
vated. The problem, though, is that the
LED indicator light does draw current —
typically about 40 mA. When the car is
not moved for a long period of time, the
battery can be affected, particularly in
cold weather. Ken wants a way to run the
LED with less current drain.

Suppose there were a way to keep the
LED turned off most of the time, and on
for only short periods. Then, the
“heavy” battery drain would occur only
in short bursts as the LED was turned on
briefly. That would not only solve the
main problem but, in my opinion, provide
a better indicator — a flashing light usual-
ly attracts more attention than a steady
one.

Of course, there are many ways to
make an LED flash, but one of the simpl-
est is to use a 3909 LED flasher/oscillator
IC. The best thing about it (from Ken’s
viewpoint) is that the operating current is
1 mA — and usually less, depending on
the applied voltage (6.4 volts maximum).

The circuit, in spite of the current peaks
on flashes, draws only about !4o the pow-
er used by an LED alone. Add to that the
reduced average-current as the flash rate
is lowered and you are have an in-

AN INVITATION

To better meet your needs, “Hobby
Corner” will undergo a change in di-
rection. It will be changed to a
question-and-answer form in the near
future. You are invited to send us
questions about general electronics
and its applications. We’ll do what we
can to come up with an answer or, at
least, suggest where you might find
one.

If you need a basic circuit for some
purpose, or want to know how or why
one works, let us know. We’ll print
those of greatest interest here in
“Hobby Corner.” Please keep in mind
that we cannot become a circuit-
design service for esoteric applica-
tions; circuits must be as general and
as simple as possible. Please address
your correspondence to:

Hobby Corner
Radio-Electronics
200 Park Ave. South
New York, NY 10003

\0K

4-AA/V

12 Cl
WVC I OQO
M.P

L£D

r®

-■!(-

41 omF

FIG. 1

significant load for a car battery.

Figure 1 shows a schematic of a simple
3909 flasher circuit operated from a 12-
volt source. The 10K resistor drops the
voltage to the four volts needed to operate
the IC. It also restricts the current that
flows when the LED does flash. Capaci-
tor Cl is needed to provide that burst of
current.

The flashing rate is determined by the
value of capacitor C2. I suggest that the
rate be made fast enough for the LED to
attract attention, but not too fast — the fas-
ter it flashes, the more current you’ll
need. If C2 is 220 /jlF the rate is about one
Hz. For a rate around four Hz, use a 1000
jjlF capacitor.

If there is a voltage source between 1 .5
and 6 volts available, just omit C 1 and the
10K resistor. I hope this little circuit
meets your needs, Ken.

Battery voltages

Peter Poulos in our nation’s capital
wonders why all batteries of the same size
don’t have the same output voltage. (I
guess he also is wondering why many
batteries of different sizes do have the
same output voltage.) Well, Pete, it all
depends upon the materials of which
the batteries are made. Different metals
separated by different chemicals (called
electrolytes) will produce different volt-
age potentials.

Let’s make a few simple batteries to see
how it works. Get a couple of paper cups

and put salt water in one and lemon juice
in the other. Now find a piece of copper
wire, a piece of aluminum wire, and a
shiny nail. Clip different pairs of the three
metals to the leads of your voltmeter (set
on the one- or two-volt scale) and dip
them into the two solutions.

You will find that your “batteries”
will produce potentials of from 0. 15- volt
to over a half of a volt. Try some other
solutions and other metals (especially an'
old silver coin if you can find one). What
combination can you find to give the
highest voltage?

Yes, those really are batteries (actual-
ly, wet cells). I wouldn’t care to hook
them together and carry them around in
my flashlight, but they will do real work.
Folk who lived out in the country often
used similar power sources for early
radios. But let’s stick with the “dry
cells” that we’re familiar with. In those
batteries, the electrolyte material, which
is usually damp, is considered to be
“dry.”

There you have the basic principles that
you need to answer your question, Pete.
Of course, sometimes the manufacturers
will fool you. They may stack several
low- voltage cells together. For example,
the common nine-volt “transistor-radio”
battery is actually a package of six small
1. 5-volt cells. In any event, now you
know why all batteries of the same size
are not the same voltage. And why some
batteries that are the same size produce
different voltages.

Young entrepreneur

I have a letter from a 1 2-year-old by the
name of Steve Knelly. (I don’t know
where he lives because I misplaced the
envelope.) The rest of us had better watch
out because this young man is going
somewhere. Steve has a videogame ma-

+5 V TO 12 v

FIG. 2

chine and he is looking for the plans for a
coin box similar to the ones used in the
arcades. He wants the box to accept
dimes, so he must realize he has to beat
the competition when he starts out. That
boy has a head on his shoulders.

Sorry, Steve, but I can’t seem to find
plans for a coin box. Perhaps you could
figure out a way to use a key-operated
switch to turn on a timer that would sup-
ply AC to the machine for a preset time-
period. Hobby Corner has discussed tim-
er circuits on several occasions in the
past. Good luck!

Sound activation

Don Dawson of Ontario, Canada needs
help on a circuit to activate some device
when sound comes out of his radio. (I’m
sure that many of you could use such a
circuit to activate something that will
wake you up when the clock radio
doesn’t.) Well, Don, the circuit you
wrote me about is on the right track, but I
would do it as shown in Fig. 2.

An audio-output transformer is con-
nected “backwards” across the audio
output of the radio. This transformer out-
puts still-higher-level audio, and it goes
to the following rectifier. Note that ger-
manium diodes are used instead of silicon
ones — the voltage drop across them is
lower.

The output at point A is just straight old
direct-current created from the audio sig-
nal fed into the rectifier. Whenever sound
comes from the radio, a positive voltage
appears. If that voltage is not great
enough for your purposes, an audio
amplifier can be added between the trans-
former and the rectifier.

The DC output (at A) can be used for a
variety of purposes. It can turn on a signal
light, sound a tone, or do almost anything
else. Not knowing what use Don intends
for the device, I have shown a 2N2222A
transistor switch connected to the output,
but almost any NPN transistor can be
used. As shown, the switch output varies
between ground and the applied voltage.
The circuit could as easily activate a relay
or other low- voltage device. Of course, if
your relay is sensitive enough, it can be
operated right from point A without the
need for the transistor switch.

Experiment!

Before closing this month’s column, I
would like to preach a small sermon. Sur-
prisingly often, the mailbag contains a
letter that refers to a circuit published
here, in another article in Radio-
Electronics, or even in another maga-
zine. The question usually goes some-
thing like this: “Wouldn’t it work better if
you connected A to C instead of to B?” or
“What would happen if you connected a
wire from X to Z?”

Well, friends, let me suggest that you
get down and dig into the matter for
yourselves. Study the circuit as best you
can and then try it out. If there are costly

.. OF ALL THE MICROWAVE

DEVICES AVAILABLE ONLY
THE ET-1000 . . ,

PORTABLE

“POCKEr

SETS
ON TV!

Versatility — Works indoors. Channels 2 & 3.

(Of you specify) color or 8&W TV Great for
apartments, hotels, office ho ildi ngs, ■

; an outdoor anten m

cannot be used. Works best above ground level.

Description — All metal construction, high
concentration parabolic reflector with dual
;'-ele : A^^ at focal point

lor maximum gam. One year tn testing and
r.deVf w ar ra n ty , parts & tabor
Personal check. M.O. - Return address, plus
$4.00 handling. Tex. re$. add 5% sales tax
,1214} 3412339/. " V.T-' '

VIDEO ENG Supply Co.

9794 Forest Ln., Suite 106 • Dallas, Texas 75243

CIRCLE 15 ON FREE INFORMATION CARD

The world of
electronics
gee- wizardry

-YOURS FREE.

32-pages of test instruments — from the
latest digital multimeters to the famous
EICO scopes. Security systems. Auto-
motive and hobbyist products. Kits and
assembled. EICO quality. EICO value.
For FREE catalog, check reader service
card or send 50^ for first class mail.

108 New South Road
Hicksville, N.Y. 11801

CIRCLE 59 ON FREE INFORMATION CARD

components involved, take whatever me-
asures you can to protect them and experi-
ment. Even a failed experiment is of
value — you’ll learn what not to do the
next time!

It’s easy to try out different things
when you use a solderless breadboard.
Just build a circuit on it and then start
changing component values or con-
nections until you find the combination
that makes the circuit perform best. I
learn quite a bit by experimenting — you
can do the same. R-E

LECTR0NIC

>MQSICIANS

Even if you know an ohm from a volt, Craig
Anderto^S-f»ewTy revised and expanded book shows
you how to build 27 accessories that enhance your
sound and broaden your musical horizons.

If you’re an old hand at musical electronics, you’ll
really appreciate that all of these processors, from
Tube Sound Fuzz to Phase Shifter are compatible
and work together without creating noise, signal loss,
bandwidth compression or any of the other problems
common to interconnecting effects from different
manufacturers. There’s even a complete chapter on
how to modify and combine effects to produce your
own custom pedal board.

Low cost project kits available from PAIA help make
even your first exposure to electronics a pleasant,
hassle-free experience and thanks to the sound sheet
demo record bound into the book you know just how
the completed device will sound before you even start.

CHARGE TO VISA OR MC TOLL-FREE

1-800-654-8657 9amu>5pmcst mon-fri

DIRECT INQUIRIES TO:

BMA Electronics, Inc.

1020 W. Wi I shire Blvd., Oklahoma City, OK 73116 - (405)843 9626

l I RUSH MY COPY OF “ELECTRONIC PROJECTS FOrTl
MUSICIANS”, $14.95 plus $1 postage enclosed.

I ) SEND FREE CATALOG OF OTHER PAIA PRODUCTS .

“ They demand a franchise fee or they’ll
knock out our satellites.”

| RQiA Electronics, Inc. |

Dept. 5R, 1020 W. Wilshire Blvd., Oklahoma City, OK 731 16

CIRCLE 52 ON FREE INFORMATION CARD

city_

. state _

JULY 1983

RADIO-ELECTRONICS

THE DRAWING BOARD

Increasing current-handling capability of regulators

ROBERT GROSSBLATT

THE TREND IN MODERN LOGIC FAMILIES IS

to make them operate with smaller and
smaller amounts of power. (I suppose the
ultimate goal is the family that can run on
potential energy!) Lower power-
requirements get rid of the necessity for
wrist-thick cables and glass insulators,
but there’s an even more important bene-
fit. Lower power means smaller, and less
complicated, regulator circuits. Some
IC’s even have the regulator circuitry
built onto the chip’s substrate. Less
current-draw means that the layout of the
+ V run on printed-circuit boards is much
simpler. Remember that when heavy
amounts of current are running through a
trace on a board, a potentially trouble-
some voltage drop will be generated be-
cause of the resistance (however small) of
the copper trace. That can lead to in-
ductive oscillation and other nightmares.

That “low power’’ side benefit,
however, can tend to make you a bit
forgetful when you’re developing a pow-
er supply. LED’s, relays, and other things
can still gobble up current at an alarming
rate. A power supply that can deliver half
an amp may seem perfectly adequate for,
say, a CMOS circuit— and it is. Un-
fortunately, when we start asking the cir-
cuit to turn something on or light some-
thing up, the current draw is going to
increase dramatically and our half-amp
supply is rapidly going to drop dead.

The voltage-regulator circuit that
we’ve been developing over the past few
months can so far safely supply about a
half amp over its full range, but it’s a
smart move to design it so that it can
provide a lot more. Since the internal
circuitry of the 7805 is limited to less than
one amp, it’s obvious that we’re going to
need some other device to provide the
additional current.

Adding a pass transistor

In Fig. 1 , we’ve added a transistor and
a resistor to take care of the additional
current. For simplicity’s sake I haven’t
drawn in the rest of the circuit we’ve
developed so far. All the current that goes
into the regulator has to pass through R B
since it’s in series with the regulator in-
put. Ohm’s law tells us that as the current
flow through a resistor increases, so does
the voltage developed across it. The base-
emitter junction of Ql, a PNP transistor,
is in parallel with R B . As long as the
current flowing through the resistor is be-

TT *

- +v REGULATED

FIG. 1

low a certain level, just about all that’s
going to happen is that the resistor will get
a little warm. At some point, however,
the voltage drop across R B is going to get
high enough to turn on the transistor,
which will start to pass current through its
collector. That current is added to the
current supplied by the regulator and al-
lows the draw on our power supply to be
increased by the amount that the Ql can
handle without blowing up.

Transistor Q 1 , then, is used as a switch
that senses when the regulator output is
near some limit and turns on to provide
the extra current that the regulator can’t
handle. The turn-on point of Ql is de-
termined by the value of R B and the base-
emitter voltage of Ql . One other thing to
be aware of is that the difference between
the input and output voltages is going to
change. Since Ql and R B are in series
with the regulator input, the voltage drop
across them has to be added to the in-
herent 2-volt drop of the regulator. That is
important to remember when we’re figur-
ing out how much voltage we need at the
output of the rectifier.

Short-circuit protection

Before we start doing any arithmetic to
calculate the value of R B we have to add
some short-circuit protection to the cir-
cuit. I know you’re thinking that we took
care of that earlier, but we’ve now added

active components to the input. If the
output is shorted now, all our earlier pro-
tection springs into action — but it only
takes care of the regulator. The collector
of Ql is going to be shorted out and the
transistor is going to start passing current
through the short. It will rapidly exceed
its maximum collector-current rating,
and all you’ll be able to do is administer
the last rites.

That is, to say the least, an undesirable
state of affairs. In Fig. 2 we’ve added a
safety net for Q 1 in the form of Q2 and
R s . Those of you with sharp eyes will
recognize that those two new components
form a switch in exactly the same manner
as R b and Ql . The same sort of analysis
also applies.

All the current that flows through Ql
has to pass through R s . When a certain
point is reached, the emitter-base junc-
tion of Q2 is going to conduct and the
transistor will turn on. When it does, it
will lower the voltage across R B and turn
Ql off. Since Q2 isn’t going to turn on
until the power supply is providing really
large amounts of current, we need a hefty
transistor there. It has to handle pretty
close to the sum of the short-circuit cur-
rents of both the 7805 and Ql .

Since there are more components con-
nected in the circuit between the base and
emitter of Ql , the math needed to calcu-
late the values of the two resistors is going
to be more complicated. Rather than go-
ing through it however, let’s make a few
intelligent assumptions and see if we can
make life easier.

If we use silicon transistors for Ql and
Q2, we know that the base-emitter volt-
age is going to be about .65 volts when the
transistor is turned on. As long as the
voltage is below that, the transistor will
be turned off.

Now let’s look at Fig. 1 again and
assume that Ql isn’t there. The 7805
needs about 8 mA to operate — the rest of
the current it passes is available to what-
ever circuit it’s powering. The regulator
can handle half an amp without any prob-
lem, but let’s be on the safe side and
arrange for Q 1 to turn on when the regula-
tor draw exceeds 250 mA. Since the turn-
on voltage for the transistor is 0.65 volts,
calculating the value of R B is a snap: R B
= E/I = .65/. 250 = 2.6 ohms

Now, it’s true that the emitter-base
junction of Ql is in parallel with R B so
that bunch of arithmetic isn’t strictly cor-

rect. Remember, though, that the appar-
ent resistance of the junction when the
transistor is in cutoff is pretty high. It’s
not really accurate to talk about the resist-
ance ot a transistor (or any semiconduc-
tor, for that matter), because they’re
dynamic devices and we should more pro-
perly refer to their k ‘impedance.” That’s
the DC resistance coupled with an AC
component. For our “real world’’ circuit,
however, the difference doesn’t amount
to much and we can ignore it.

If you look at Fig. 2, you’ll see that we
have to go a little farther in figuring the
value of R b . Since both R B and R s are
across the emitter-base junction of Ql,
both their values have to be taken into
account when we figure the trip point of
Ql. Once again, the “resistance” of Q2
in cutoff is high enough for us to ignore it
and just work with the resistor values.

Since R s has to pass all the current that
flows through Q 1 , we have to decide what
we’re going to let the maximum current
be. Five amps is a good value for our
regulator circuit — more than that will
cause design problems we don’t want to
get involved with. Just as was the case
with Ql, Q2 will start conducting when
its emitter-base voltage reaches 0.65
volts. If we want that to happen when Ql
is passing 5 amps, R s has to be on the
order of 0. 13 ohms. The total resistance
we need to turn on Ql is 2.6 ohms. Since
Rs must be . 1 3 ohms, the new value of R B
will be 2.47 ohms.

Now, I’m the first to admit that those
are pretty oddball values for resistors.
You can’t exactly amble down to your
local resistor store and buy a 2.47 ohm
resistor. There are ways around that,
though.

Next month we’ll take care of all the
unfinished business and complete our
regulator. We’ll consider choices for Ql ,
Q2, and the proper wattage for the resis-
tor. Not only all that, but, since we’ve all
been working so hard we’ll find ourselves
treated to a surprise in the circuit that’s
not only useful, but that’s one we get for

”l'm not too thrilled with its aesthetic
value , but I sure dig the variety ' of chan-
nels I can get.”

f HOBBY MICROWAVE ANTENNAS A

“COMPLETE SYSTEMS”

65 COAX 3 COAX TUNER W/SYSTEM “NOT FOR S T S”
WE REPAIR ALL MICROWAVE $17.00

CORD-FREE
UP TO 1 MILE RANGE
“PACER”
MULTIPLEX
$297.50

"TRUE TOUCH TONE"

DEALER PROGRAMS AVAILABLE

■COMPLETE BOMAN PRODLIN
SATELLITE SYSTEM $2250.00

.JBaCF^GF

14824 CAMDEN AVE. SAN JOSE, CA. 95124
(408) 266-1511

CIRCLE 57 ON FREE INFORMATION CARD

We Have The Books You Need

□ ART OF PROGRAMMING THE IK ZX81.

How to use the features of the ZX81 in programs
that fit into the IK machine. 96pp. $5.75 postpaid.

□ ART OF PROGRAMMING THE 16K ZX81.

How to use your 16K RAM pack and ZX printer to
the full. 144 pp. $6.95 postpaid.

□ ART OF PROGRAMMING THE ZX SPECTRUM.
Everything you need to know to put the ZX
Spectrum to work for you. 144 pp. $8 postpaid.

ELECTRONIC TECHNOLOGY TODAY, INC.
P.0. BOX 83

MASSAPEQUA PARK, NY 11762

Name:

Address:

L City: State:.

[^Number of books ordered

( POWER UNC PROBLEMS? \

SPIKE-SPIKERStm. . .The Solution!

Minimize equipment damaging spikes and conducted RF noise
to or from sensitive equipment. Transient surge protection
plus low pass RFI hash filtering. All units 1 20V 1 5A.

DELUXE $79.95

Dual 5-stage filtered
ckts. 8 switch sockets
main switch, fuse, light

MINI II $44.95

Wall Mount
3-stage filter
2 sockets

QUAD II $59.95

Wall mount. Dual 3-stage filter
4 sockets & light

U H

Order Factory Direct

215-865-0006

Kalglo Electronics Co., Inc.

65 84 Ruch Rd., Dept. T©

Bethlehem, PA 18017

Out of State

DEALERS INVITED 800-523-9685

PA Res. Add 6% • COD add $3.00 + Shipping

CIRCLE 46 ON FREE INFORMATION CARD

BIG

PERFORMANCE

small

PACKAGE

Model 240

Video Generator

• Video output for all VCR, CCTV and
Monitor Applications + 1 volt into 75 ri
load

• RF output: CH 2, 3, 4

• Scope trigger output for V or H sync

• 10 step gray-scale staircase signal
for video circuit analysis

• 10 bar and 3 bar gated rainbow pattern

• 8 other dot, bar and line patterns

• Operates from 2 std. 9V batteries or
115VAC

• Single slide switch control

• Complete with test leads, protective
cover, AC adapter, comprehensive
instruction manual

PRICED UNDER $200.

THE 240 DOES SO MUCH
FOR SO LITTLE!!

THE HICKOK ELECTRICAL INSTRUMENT CO.
10514 Dupont Avenue . Cleveland, Ohio 44108
(216) 541-8060 . TWX: 810-421-8286

CIRCLE 85 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

STATE OF SOLID STATE

Power MOSFET amplfiers

ROBERT F. SCOTT, CONTRIBUTING EDITOR

SOME OF THE NEWER HI-FI AMPLIFIERS

are designed around power FET’s in the
output stage. That’s because they offer
low harmonic distortion, extended SO A
(Safe Operation Area), and infinite cur-
rent gain. The design, construction, and
performance of such an amplifier is
covered in a recent Intersil applications
note. Its schematic diagram is shown in
Fig. 1. The amplifier delivers 50 watts
into an 8-ohm load. Its frequency re-
sponse is ± 3-dB from 20 Hz to 100 kHz
while distortion is less than 0.25% from
20 Hz to 20 kHz.

The amplifier’s design is un-
conventional in several respects: First,
there are no rolloff or compensation capa-
citors. Instead, rolloff is provided by the
input capacitance of the power MOS-
FET ’s (Q8 and Q9) that are arranged in a
quasi-complementary output stage. The
driver stage uses bipolar transistors and
provides the usual voltage amplification
and phase-splitting functions. Finally,

the positive power-supply line is boot-
strapped to insure that the positive and
negative half-cycles of the output signal
are equal and maximized.

The input stage is designed around Q3,
a U402 dual N-channel JFET in a differ-
ential configuration. A pair of J 1 1 3
JFET’s (Q1 and Q2) provide a constant
current for the U402. That current con-
trols the bias current of the output stage
and is set by R 18, a 10-turn IK trimmer
potentiometer. Bipolar transistor pairs
Q4-Q6 and Q5-Q7 turn on in proportion
to the input signal and provide drive cur-
rent for output transistors Q9 and Q8,
respectively. The drive current flows
through R10 and Rll and develops the
necessary gate-source voltage for the out-
put transistors. The power gain of the
output stage is quite high because of the
comparatively high value of the resistors
connected between gate and source.

The boot-strapped positive power-
supply line, mentioned earlier, is needed

because if Q8 is to clip at the level of the
positive power-supply line, its gate volt-
age must be driven beyond that point.
Thus, a voltage higher than Ve must be
supplied to the input and driver stages.
Instead of using an external powersupply
with an output of more than 35 volts, the
designers elected to bootstrap the !/6-volt
supply; that bootstrap circuit consists of
D7, C4, D6, C9, and R15.

The closed-loop gain is determined by
resistors R16 and R17. Capacitor C3
compensates for any offset in the output.
In this design, the open-loop gain is set at
20 kHz by the gate capacitance of the
power MOSFET’ s and the values of the
gate resistors, R10 and Rll. This fre-
quency can be pushed higher by reducing
the value of the gate resistor. However,
this will increase the power dissipated in
the driver stage — particularly in Q6 and
Q7.

Data for this section of the column was
taken from a pre-published copy of
Application Note A0-40 (A Low-Cost
Audio Amplifier Using Power MOS-
FET’s by Bruce Rosenthal and Jim
Meador) from Intersil, Inc., 10710 N.
Tantau Ave., Cupertino, CA 95014.

High-voltage trigger

A series of new semiconductor devices
for high-voltage bilateral trigger applica-
tions has been introduced by Motorola.
Known as SIDAC’s, the devices combine
the high-voltage bilateral trigger func-
tions of triacs with the simplicity and low
cost of two-terminal diac triggers. The
devices replace less reliable components
such as neon bulbs for applications such
as: high-voltage regulators, strobes and
flashers, ignitors, line-transient clippers,
pulse generators, fluorescent lighting,
and high-pressure sodium-vapor lighting

The devices are designed for direct in-
terface with the AC power line. Upon
reaching the breakdown voltage in each
direction (104 to 135 volts) the SIDAC
switches from a blocking state to a low-
voltage “on” state. Conduction
continues — as in an SCR — until the main
terminal current falls below the holding
current, typically 100 mA.

The new MK1 V series of SIDAC’s in-
cludes three devices, the MK1V-115,
MK1V-125, and MK1V-135; with the
last three numbers indicating the max-
imum repetitive break-over voltage. Fig-

figTT

ure 2 shows two SIDAC circuits; Fig. 2 -a
shows how electronic equipment can be
protected against line-voltage transients
and Fig. 2 -b shows a SIDAC as a two-
terminal trigger for a strobe or flasher
application.

117
V AC

SIDAC

ELECTRONIC

EQUIPMENT

BRIDGE

VAC

FIG?

The minimum breakover (breakdown)
voltages are 104, 110, and 120, respec-
tively for the three devices. Off-state re-
petitive voltage is ± 90 volts and repeti-
tive peak off-state current is 10 /jlA. In-
stanteneous on current is 1.0 amp RMS
for each device. Maximum breakdown
current (60-Hz sinewave) is 200 p A. For-
ward “on” voltage is typically 1.1 while
dynamic holding current is 100 mA.

Transistor data book

Field-Effect Transistors — Selector
Guide and Cross Reference is a 32-page
booklet chock full of valuable informa-
tion on FET’s. It opens with a brief de-
scription of all types of field-effect tran-
sistors and then comparing FET’s to bipo-
lar devices and then JFET’s versus MOS-
FET’s. This is followed by many listings
of pertinent characteristics of JFET’s,
single- and dual-gate MOSFET’S, dual-
gate DMOS as well as power MOSFET’s.

A numerical index lists approximately
70 devices whose characteristics are
listed in tables depending on their
classification as Switches and Choppers,
Power MOS, Low-Frequency Low-
Noise Amplifiers, or High-Frequency
Amplifiers. A Cross-Reference and In-
terchangeability Guide matches industry
type numbers of approximately 1900
FET’s with equivalent types from Motor-
ola. The book concludes with illustrated
FET applications that include an
ionization-chamber smoke detector and a
500-MHz dual-gate MOSFET amplifier
that is suitable for service in the front-end
of a communications receiver. —
Motorola Semiconductor Products, PO
Box 20912, Phoenix, AZ 35036.

continued on page 89

■ ■ " : [r :

Quick charge cordless

soldering iron, up to 125
electronics joints per
charge. Total recharge
in less than 4 hours,
isolated tip design. One
of more than 2 dozen
ISO-TIP and ORYX irons
available. Write for free
catalog and name of
nearest distributor.

A Hot Tip on
Cordless

No. 7700
QUICK CHARGE
Cordless
Soldering Iron

ORYX

WAHL CLIPPER CORPORATION

Sterling, Illinois 61081 • (816) 625-6525

CIRCLE 19 ON FREE INFORMATION CARD

Radia Electronics BOOKSTORE

□ Build Your Own Satellite TV Receiver $7.00

□ 8-Ball Satellite TV Antenna $5.00

□ Build Your Own Robot $12.00

□ TV Descrambler (January, February 1981) $3.00

□ Video Entertainment (January 1982) $2.00

□ Your Own Computer (October 1981) $3.00

□ Radio-Electronics back issues (1983) $3.00

(January, February 1983 not available)

Write in issues desired

□ Radio-Electronics back issues (1982) $3.00

(January 1982 not available)

Write in issues desired

To order any of the items indicated above, check off the ones
you want. Complete the order form below, include your pay-
ment, check or money order (DO NOT SEND CASH), and mail
to Radio-Electronics, Reprint Department, 200 Park Ave.
South, New York, NY 10003. Please allow 4-6 weeks for
delivery.

If you need a copy of an article that is in an issue we indicate is
unavailable you can order it directly from us. We charge 500
per page. Indicate the issue (month & year), pages and article
desired. Include payment in full, plus shipping and handling
charge.

□ Radio-Electronics back issues (1981) $3.50

(March, December 1981 not available)

Write in issues desired

□ Special Projects (Winter 1980) $4.00

□ Special Projects (Spring 1981) $4.00

□ Special Projects #4 (Summer 1982) $4.00

□ Special Projects #5 (Winter 1983) $3.00

□ Special Projects #6 (Spring 1983) $3.00

□ Radio-Electronics Annual 1983 $2.50

□ How to Make PC Boards $2.00

□ All About Kits $2.00

□ Modern Electrics (Vol. 1. #1, $2.25

April 1908)

□ Electro Importing Co. Catalog $4.95

(1918) (176 pp)

ARTICLE

MONTH YEAR

PAGES

@ 500 each

TOTAL PAGES TOTAL PRICE

MAIL TO Radio-Electronics 7 83

Reprint Department, 200 Park Ave. South, New York, NY 10003 All payments must be in U.S. funds

Total price of order $

Sales Tax (New York State Residents only) $

Shipping & Handling (U.S. & Canada only) (Includes FIRST CLASS POSTAGE) $1.00 per item $

All other ($2.00 per item, sea mail) $

($4.00 per item, air mail) $

Total Enclosed $

Name

Address.

City.

State.

Zip.

JULY 1983

RADIO-ELECTRONICS

SERVICE CLINIC

A dish full of bugs

JACK DARR SERVICE EDITOR

SATELLITE-RECEIVING SYSTEMS HAVE BE-

come very popular of late, especially in
rural areas where cable TV is pretty cer-
tain to remain merely a dream. Such sys-
tems, and the large outdoor antennas that
they use, have their own peculiar prob-
lems, some of which can really “bug”
you if you don’t recognize the cause.
Here are some cases that you may find
interesting.

In the first case, the system had been
working well, until suddenly the recep-
tion started getting worse and worse, and
finally went out completely. Checks of
the system showed nothing out of order in
the electronics — LNA, downconverter,
etc. That left only the dish antenna. Noth-
ing was immediately apparent, but close
examination finally showed the cause.

FIG. 1

A parabolic dish reflects the 3-4-GHz
satellite signals on to a structure called a
feed horn at the focal point of the dish (see
Fig. 1). The feed horn directs the signal
on to a small pickup device. There are
various ways of picking up the signal;
some antennas use very tiny dipoles, oth-
ers use a waveguide, and so on. But one
thing is common to all designs — there is a
small hole at the end of the feed horn that
the signal must pass through. In this case,
the hole had been chosen by a female
mud-dauber wasp to make her nest in.
That busy little bug finds a deposit of wet
clay, and carries vast quantities of it, con-
sidering her size, to your garage eaves, or
anyplace else she can find to build nests,
which are long tubes of clay. She loves to
use holes in anything she can find —
garden hose stored for the winter, a set of

socket wrenches in an open toolbox, a
paint spray-gun left on the bench; etc. In
this case, she had adopted the end of the
feed horn — and it’s hard to get a signal
through a couple of inches of wet clay.
Cleaning the aperture out, and guarding
against further problems by tying a small
piece of plastic wrap over the end, cleared
up the problem.

In the second case the system worked
nicely during the day, but at dusk the
reception gradually got worse until it quit
altogether. Once again a wasp eventually
proved to be the source of the problem.
That one is called the paper-making wasp;
their nests, found under eaves, etc., look
like a cone made of paper. Those wasps
also like to adopt any kind of hole as their
own. They were settling in the horn, and
getting ready to build their nest there.
During the day, they were all out fora-
ging; at dusk, they came back and
crawled into the horn. This is a big wasp,
and it didn’t take many to fill the feed
horn completely.

Here’s a word of caution. Those red-
bodied wasps have a nasty disposition and
when they sting you you’ll know it. The
best way to deal with them is to spray the
feed horn with a strong wasp killer while
it’s “occupied,” and come back later to
clean it out. Once again, cover the open-
ing with plastic wrap to prevent any future
problems.

A different kind of animal

The last case we’ll talk about deals with
another kind of animal , one that can do far
more damage. The animal I am talking
about is man, and in particular the type of
man that doesn’t think.

One such critter was working as an
assistant to a dish installer. The installer
wrote me asking for help (incidentally,
this is the only case of satellite trouble
we’ve ever fixed — by mail, of course).
One of his customers had complained that
the system got very noisy in rainy wea-
ther. I told him to tighten all the coax
fittings and then spray them with a clear
acrylic coating to weatherproof them.
The installer then sent his assistant out to
spray the plugs. Spray them he did — with
a penetrating oil (the fellow simply did
not read the label before doing the job).
Of course, the oil not only penetrated the
plugs, but went right down to the coax’s
center conductor, dissolving the insula-
tion as it went. All the coax had to be

replaced — which was expensive, to say
the least. The moral of the story is: When
you give someone instructions to do a job,
make sure everyone understands exactly
what’s to be done. Otherwise, you’re in-
viting disaster. R-E

SERVICE

QUESTIONS

TWO HINTS

Here are a couple you might be in-
terested in. I had a Wollesak 3M tape
recorder that would not run in one direc-
tion. It had an odd clutch setup; when the
direction was reversed, the idler ran up a
spiral groove to engage the other drive.
After cleaning the grooves, the idler
worked, but the clutch facings were so
badly worn that they slipped. The fix
turned out to be fairly simple. We got
some fairly thin gasket material from an
auto supply store, and cut two new clutch
facings out of it. Those were cemented to
the idler and the whole thing works better
than new.

The second hint is for those into restor-
ing old radios. A good place to find in-
formation about parts and services is
Hemmings Motor News , Box 380, Be-
nnington, VT 05201. Their classified
section includes ads for various com-
ponents, as well as for such services as
reconing speakers and restoring wood
veneer.

Thanks to Rodney K. Schrock of
Somerset, PA for these.

BURNING RESISTOR

I repaired a Setchell-Carlson 3C66, in-
cluding installing a new CRT and so on. I
noticed that the 22K resistor between the
cathode of the 3A3 and the plate of the
6BK4 had burnt up and replaced it with
one of equal value , but rated at 2 watts.
The set worked and the customer took it
home. A while later I got a call — the set
had gone out again. When I got it back into
the shop, I found that the same 22K resis-
tor was once more charred beyond
recognition. I’m puzzled; is it possible that
a common carbon resistor won’t work
there?— L.P., Osceola, I A

I think your guess is right. I’ve had
some embarrassing experiences trying to
use common carbon-types in high-
voltage circuits. The best bet here would
be to use a glass-film or flameproof type.
Carbon resistors, when used in high-
voltage circuits, have to handle a lot more
power than you might suspect at first
glance. As a result, they get hot and burn
up.

To tell you the truth, I’m not sure what
that resistor is doing there anyhow. The
only other time I’ve seen something like
that was in an old Zenith. Incidentally,
that resistor, which was a IK unit, also
burned up regularly. We eventually re-
placed it with a short piece of heavy hook-
up wire.

WHICH CAPACITORS?

In the February, 1983 issue of Radio-
Electronics you had a question about
“flag waving” (instability) in older sets
when using a VCR. We have a CTC-68
(1973) with that problem. You said to re-
duce the value of the AFC capacitors; are
those the ones that are called out as C2
and C3 in the MAH001A module in that
set? — L.K., Newark, CA

I took a look at the Sams Photofact
(number 1378-2), and I’m pretty sure that
they are; try smaller ones there. You
might also try reducing the value of the
100K resistors, although I’ve never heard
of anyone having to do that.

POSSIBLE CURE

A recent letter in your column de-
scribed a problem with a Zenith
16Z7C19Z that was destroying 6HV5’s; I
may have a solution. In several of those I
have found that the tube’s screen resistor,
a IK unit, has either increased in value or
opened. If that happens, it may produce
the symptoms observed. If the 6HV5 has
to be replaced, it is a good practice to
check that resistor, especially if the tube’s
glass is cracked; the resistor can be check-
ed from the top of the chassis. Hope that
helps — Robert Cortner Jr., Davison TV,
Buffalo, MO

VERTICAL PROBLEM

I have a Sears 528.41670314 with
nothing but a bright horizontal line on the
screen. The sound is OK. I checked the
vertical circuit and found one problem:
There was — 50 volts on V6A where there
should have been +300. I scoped the
boost that fed that plate and found a very
high ripple- voltage. Replacing Cl 13C in
the + 300-volt line cleared up that prob-
lem. The moral is that you should always
scope the B + lines.

That bad capacitor was evidently
allowing feedback that was upsetting
everything. Incidentally, When you see
mysterious vertical lines at one side of the
picture, and the set uses flyback-derived
low-voltage sources, always scope those.
You may find, as we did in several sets,
that the small filter-capacitor on the low-

YOUR EXCITING
NEW HOBBY!

Enjoy fantastic savings by assem-
bling your own organ or piano.

“!> It's easy. No technical
knowledge required.

Just follow our clear,
pictured instructions.

® Choose from many models
from portables to consoles.

Ask about our interest-free
installment plan.

(fii) [TTrar3Hfl

ORGAN & PIANO KITS

/ . For Free Information Pack M40

Call Toll Free

— ^ " ' ’ ’ 1 1 \ 800-233-3865

Ivin PA 717 299 4327

WERSI Dept M40 P.O.Box 5318
Lancaster, PA 17601

□ Free Info. Pack: □ Organ □ Piano

□ Catalog & Demo Record tmciose $6)

Name

Address

City

Phone ( )_

_ State_

- Zip-

Rep inquiries invited

CIRCLE 95 ON FREE INFORMATION CARD

voltage supply is open and you're getting
a ripple voltage at the horizontal fre-
quency!

Thanks to Lesley F . Dahm for this.

REPLACEMENT 1C

I need a replacement or substitute for
IC-200 in a K-Mart SKC-1940-AM; the part
number is 56A49-2 or 56C49-2. I’ve looked
everywhere I can think of.—C.H., Liberty
Lake, WN

That set was made by Admiral for the
Kresge Co. To my surprise I found a
listing for the IC in the Sylvania ECG
guide; it’s an ECG-854. Incidentally, the
letter in most Admiral part numbers
doesn’t mean much, hence both part num-
bers you listed are the same. If you need
other Admiral parts, and can’t get them
locally, try their WATS-line number: 1-
800-447-836 1 . Be sure to have the correct
Admiral part number handy or they can’t
do much for you.

CLOCK IC

An Imperial clock radio, model CR-
102, made for Superscope, was stuck in
the calendar mode. The data sheet for the
clock IC, an Electronic Arrays 7317,
showed that an internal pull-down resis-
tor at pin 24 enables the clock mode un-
less V S s (20 volts in this case) is applied
to the pin. When I measured, I found the
continued on page 99

GET

MICROCONTROL
WITH SAMS.

This fascinating book shows how
you can turn a low-cost computer
into a dedicated microcontroller for
a robot, your home's environment,
games, instruments, and more! You
can even design your own micro-
controller from scratch!

No previous design experience is
needed. Just your brain, a microchip
and Sams MICROCOMPUTER
DESIGN AND TROUBLESHOOTING.

Starting with the basic controller
functions, it covers sequencing,
counting, timing, computation and
management. It also answers such
questions as, "What is a develop-
ment system?" and "Can you use a
Motorola chip with an Intel proces-
sor?" It even discusses how to put
together a simple test instrument
for locating board faults and other
useful troubleshooting techniques.

Also included are detailed
chapters on read/write timing,
interfacing ROM and RAM, bus
schemes, address decoding and
other important design and system
considerations. MICROCOMPUTER
DESIGN AND TROUBLESHOOTING is
like having a computer consultant
in your pocket, yet it costs only
$ 17 . 95 !

Get your hands on a copy and
get computer control! To order
MICROCOMPUTER DESIGN AND
TROUBLESHOOTING (No. 21819),
call 800-428-3696 or 317-298-
5566 and ask for Operator 393.

SAMS BOOKS AND SOFTWARE

HOWARD W. SAMS & CO., INC.

4300 West 62nd Street
P.O. Box 7092
Indianapolis, IN 46206

Offer good in USA only and expires 10/31/83.

Prices subject to change without notice. In
Canada, contact Lenbrook Electronics,

Markham, Ontario L3R 1 H2. AD393

CIRCLE 32 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

Without question, microcomputers ,
state of the art in electronics. And I
only home study school that offers \
training for this booming field with
of 3 production-model micro compi
We’ll explain the principles of tro
shooting and testing your microcom
best of all, we’ll show you how to
program it to do what vou want.

believe
that training
on production

model equipment, __
rather than home-made learning devices,
makes home study more exciting and rele-
vant. That’s why you’ll find such gear in
most of NTS’s electronic programs.

For instance, to learn Color TV Ser-
vicing you’ll build and keep the 25"

(diagonal) NTS/HEATH digital color TV.

In Communications Electronics
you’ll be able to assemble and keep
your own NTS/HEATH 2-meter FM
transceiver, plus test equipment.

But no matter which program you
choose, NTS’s Project Method of instruction
helps you quickly acquire practical know-how,

1. The NTS/Rockwell AIM 65
Dedicated Microcomputer A Single
board unit featuring on board
printer and display— 4K RAM
(expandable). Application Functions:
Central processor— Controller/Monitor—
Development System. 2. “The
NTS/SYM-1 Microcomputer” 6502
Based CPU— 4K bytes ROM
(expandable)-lK RAM (expandable). 51
active I/O lines for versatile interfacing: disk
drives, ASCII key boards, cassette tape, etc.

Simulated TV Reception

NATIONAL

TECHNICAL

SCHOOLS

3. The NTS/Heath HN-89A Microcomputer

features floppy disk storage, “smart” video
terminal, two Z80 microprocessors, with
32K RAM Memory, expandable to 64K on
board. 4. The NTS/Heath GR 2001 Digital
3 . Color TV (25” diagonal) features

specialized AGC-SYNC muting, filtered
color and new solid-state high voltage
tripler rectifier.

Name Age

Address

State T Zip _

1 □ Check if interested in G.l. information. ■

j □ Check if interested ONLY in classroom training in Los Angeles. J

............ ............ ........... J

Please rush FREE color catalog on course checked below

□ MicroComputers/MicroProcessors □ Auto Mechanics

□ Communications Electronics □ Air Conditioning

□ Digital Electronics □ Home Appliances

□ Industrial Technology □ Color TV Servicing

TECHNICAL-TRADE TRAINING SINCE 1 905
Resident and Home-Study Schools

4000 SO. FIGUEROA ST.. LOS ANGELES, CA. 90037

r "national" technical" schools" "

■ 4000 South Figueroa Street, Dept. 206-073

* Los Angeles, California 90037

JULY 1983

RADIO-ELECTRONICS

COMPUTER CORNER

Recently-introduced microcomputers

LES SPINDLE*

FIG. 1

NOT WILLING TO BE LEFT BEHIND WHILE

well-established computer companies like
IBM and DEC moved aggressively into
the personal-computer marketplace, vet-
eran personal-microcomputer man-
ufacturers like Tandy/Radio Shack and
Apple Computer recently came back with
a vengeance.

After months of media speculation
about its not-too- well-kept secret, Apple
unveiled its new 32/1 6-bit Lisa computer.
Both the Apple He and the simul-
taneously-announced Radio Shack Model
12 were upstaged by the attention-
grabbing Lisa.

If Lisa actually lives up to its pre-
release promises, it may well give all
competitors a run for their money. Priced
just below $10,000, Lisa barely fits into
the “personal” or “small business”
computer categories. Yet, its com-
prehensive list of features and integrated
software may well compensate for its
price. And there’s plenty of room for ex-
pansion as the applications needs grow.
But its biggest feature is its user-
friendliness. It’s aimed at those not well-
versed in “computerese.” Apple claims
that a first-time user can put the Lisa to
work in less than a half-hour.

The hallmark feature of Lisa (Local
/ntegrated Software Architecture) is the
extreme ease of use promised by its
“mouse” device. The mouse is a palm-
sized box connected to the terminal that
allows the user to manipulate a cursor just
by moving the mouse across the desk top.
Pictorial symbols, such as a file folder, a
wastebasket, and stationery, provide the
user with an immediately-identifiable
range of functions — such as filing a docu-
ment, discarding old data, or writing a
letter. By simply moving the cursor to the
desired function, the user can perform
functions that ordinarily require a good
deal of key-punching, several com-
mands — and occasional swearing by
newcomers or those not familiar with the
particular system — to accomplish.

Meanwhile, a menu at the top of the
screen continuously lists the various
functions within each application. By
simply moving the mouse to point at one
item, another detailed menu is displayed
on the screen to guide the user step-by-
step through that particular function. The

^Managing Editor, Interface Age magazine

interactive process continues, allowing
even a complete computer novice to move
quickly from one transaction to another
with a minimum of time and effort.

The range of software that comes stan-
dard with the computer is also im-
pressive, and — another important feature
of the machine — data from each package
is easily integrated with data from the
other packages through the use of the
versatile mouse. LisiCalc is an spread-
sheet program for financial planning. The
LisaWrite word-processing program in-
tegrates several text-editing functions for
correspondence, reports, short memos,
etc. LisaGraph integrates spreadsheet
data with various graphs — bar, line, bar/
line, scatter graph, or pie charts. That
program can work in conjunction with the
LisaDraw program for creating graphic
designs. The LisaList program performs
comprehensive data-base and filing func-
tions, while LisaProject handles various
critical-path and project-management
functions. And that, too, can be inte-
grated with the other programs.

To make the machine even more ver-
satile , it is compatible with either BASIC ,
Cobol, or Pascal. Two operating
systems — CP/M and Xenix — are sup-
ported.

The microprocessor for the Lisa is the
MC68000, which combines a 32-bit in-
ternal architecture with a 16-bit external
data path. The computer comes with one

megabyte of RAM. Two S^-inch floppy-
disk drives are standard and a Profile hard
disk supplies 5 megabytes of storage.

The CRT screen is a 12 inch, black-
and-white display. The resolution is 364
x 720 pixels. A typewriter-style key-
board and numeric keypad are standard.

Two serial ports and one parallel port
are included and allow for a multitude of
additional functions. The AppleNet soft-
ware package (not available as this was
written) will enable local-area network
communications. Data-base access to
The Source, CompuServe, and other such
services is possible with the LisaTerminal
software accessory.

Another new Apple

Somewhat buried under all the hoopla
surrounding Lisa , the Apple lie (e is for
“enhanced”) is a successor to Apple’s
most popular computer — the Apple II.
The system is priced below the similarly-
configured Apple II + . The 64K unit off-
ers easy expansion to 128K with a plug-in
card. A low-cost 80-column card is also
available.

The system is fully compatible with all
Apple II software on the market. Mean-
while, enhancements to existing pro-
grams are rapidly being developed by var-
ious companies to add new features that
are possible on th t Apple lie. Among new
programs are the Apple Writer II word
processor and Quick File II.

The price for a complete system (with
64K memory, floppy-disk drive with
controller card, 12-inch monitor with
stand, and the 80-column card) is $1,995.

Not to be outdone

Last, but not least, Tandy/Radio Shack
craftily unveiled its latest offering almost
the same day as Apple. The TRS-80 Mod-
el' 12 (priced at $3,199 with one disk
drive, $3,999 with two) is Tandy’s low-
cost alternative to its popular Model II.
Wjjile running all software designed for
the Model II, the system looks very much
like the 16-bit Model 16 introduced last
year.

The system includes a Z80A 8-bit pro-
cessor, direct memory access, and vec-
tored interrupts. Standard memory capac-
ity is 80K, with either one or two 1.25-
megabyte disk drives.

TRSDOS 4.2 is the unit’s resident op-
erating system— an enhancement of the
TRSDOS 2.0. Double-density disks are
supported, as well as double- or single-
sided 8-inch floppy disks.

The display is a 12-inch green-
phosphor monitor capable of 80 X 24 or
40 X 24 lines. Upper and lower case
characters are supported, as well as 32
graphics characters. A detachable key-
board includes 82 keys, with a numeric
keypad and eight special-function keys.

An optional card cage provides six
slots for expansion. An upgrade card will
convert the system to Model 16 capabil-
ity. High-resolution graphics and a 64K
VisiCalc are other possible expansions.

Meanwhile, further expansion is avail-
able with the newly introduced 12-
megabyte hard-disk drive, adaptable to
the TRS-80 Model II, 16, or 12 systems.
The price is $3,495 for the primary drive
and $2,495 for a secondary drive.

While the Model 12 unveiling may not
have been as exciting as Apple’s double
announcement, Radio Shack reportedly
has more tricks up its sleeve, including a
portable computer to rival the Osborne I
and all of its imitators. In any event, it’s
clear that the pioneer microcomputer
companies are determined not to be un-
done by the flood of competitors entering
the market. As the competition heats up,
the coming months should offer a number
of surprises. R-E

STATE OF SOLID STATE

continued from page 81

High-power 900-MHz transistors

Motorola has introduced three new 24-
volt DC, 900-MHz power transistors.
The line includes the MRF890, a 2-watt,
9.0-dB minimum-gain predriver; the
MRF892 14- watt, 8.5-dB driver; and the
MRF894 30-watt, 7.0-dB final amplifier.
A chain of those three devices is capable
of boosting a 100-mW UHF input signal
(804 to 960 MHz) to 30 watts output. The

new transistors are intended for large-
signal, common-base amplifier applica-
tions in industrial and commercial
cellular-FM radiotelephone equipment.
All three devices have guaranteed gain
performance at 900 MHz, collector
efficiencies of 55% minimum, and will
withstand a 30: 1 VSWR load mismatch at
their rated voltages and power outputs.
The MRF390 is packaged in a 305-1 case;
the other two devices in the family in
319-04 packages. Prices in quantities of
100-499 are $10.00, $19.55, and $30.60
for the MRF890, -892 and -894,
respectively . — Motorola Semiconduc-
tor Products, Attention: Tom Bishop,
PO Box 20912, Phoenix, AZ 20912.

Voltage regulator design data

Linear Voltage Regulators, (Applica-
tion Note APN-27) is a 16-page booklet
that provides detailed design information
on a wide variety of voltage-reference
circuits and voltage regulators. The mate-
rial includes schematics, performance
data, and descriptions of 18 circuits.
Those circuits include band-gap voltage
references, Zener-diode references,
series and shunt regulators, and positive
and negative voltage regulators. The de-
signs include information on such
parameters as temperature stability, noise
voltages, and line and load regulation. —
Interdesign, Inc., 1255 Reamwood
Ave., Sunnyvale, CA 94086. R-E

CIRCLE 51 ON FREE INFORMATION CARD

DON’T

FORGET

USE

YOUR

READER

SERVICE

CARD

64K Applesoft Compatible
Micro-Professor IF
$399.95

Y\&ve &

exp S££ on

m ■ n ■ t

Compatible: *Micro II is 98% compatible to Applesoft and 90%
compatible to Machine Language. Most programs written for the
Apple can be run directly or with slight modification.

Expandable! Add a printer, game paddles, floppy disk drives,
speech and sound synthesizer, and Firmware ROM cartridges to
expand the Micro II to cover many applications.

Features: •

• 6502 CPU

• 16K BYTES of ■

ROM (12K BASIC)

• 64 BYTES of RAM

• 46 one-key Basic *
Commands

• Joystick Interface "

• Video Monitor &. t
TV Interface

• Printer Interface
(Parallel)

Tape Cassette
Interface
Video Display
Memory Mapped
Into System RAM
Systems Diag-
nostic Tape
Instant Color
Graphics
Installation/Diag-
nostic/Basic
Programming
Manuals

Options: • Demo Cartridge

• Floppy Disk with ($34.95)
Controller ($395.00) • Software, cassette

Joystick Game
Controller ($24,95)
Printer Interface
cable and
software ($34.95)
MPF-11 Printer
($199.95)

’ Green Screen
Monitor ($99.95)

($8.95) disk ($34.95),
prices vary according
to application
Full size keyboard
($39.95)

MONEY BACK GUARANTEE

Order today and receive a FREE Full Size Keyboard for
the MicrO'Professor II™ — a $39.95 value.

For Fast Service Call -rfl/C Dept. RE073

Toll Free 14803 NE 40th

1 - 800 - 426-1044 ^ Redmond, WA 98052

CIRCLE 10 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

COMMUNICATIONS CORNER

Communications for the disabled

HERB FRIEDMAN, COMMUNICATIONS EDITOR

FOR ALMOST ALL MY WORKING LIFE I WAS

associated with New York City’s High
School of the Air for Home Instruction.
Using FM radio and sophisticated (for
their day) telephone couplers and switch-
ing systems, the High School of the Air
created real-time classrooms for disabled
children who could leave home only in-
frequently, if at all.

The dial-up telephone system con-
nected the homebound students to the stu-
dio console where they were mixed (elec-
tronically) with a teacher and his class.
We could do straight classroom sim-
ulations, or even dramatic programs with
music, sound effects, in-studio perform-
ers, and dial-up telephone performers.
The studio mix was then fed to the
transmitter and also out to up to 25 tele-
phone users. (The budget-cutters elimin-
ated the five teachers who serviced 1000
students, and thereby — after 35 success-
ful years — destroyed the program.)

While it was easy for most disabled
children to use the service, the blind and
deaf had severe communications hand-
icaps, which carried through to adult-
hood. There is little in the way of low-cost
communications equipment for the dis-
abled, and little information on what there
is, even from the manufacturers and dis-
tributors. (Most of them simply appear
concerned with charging as much as the
traffic will bear.) Personal computers
appeared to be an ideal solution for pro-
viding low- or moderate-cost com-
munications for the deaf and blind, but

again, there is no centralized information
source.

When several of our readers with dis-
abled children inquired about using per-
sonal computers for communications, I
ran up against the same problem they
did — too little information. By chance, I
got to talking with some people at The
Source about the problem, and it turned
out that they were working toward a simi-
lar goal of providing a bulletin board and
information database for the disabled. In
less than two weeks the system was in
place.

Users of The Source can go directly
from the command mode to a bulletin
board and message center for the disabled
by typing “POST R DISABILITY” on
the terminal. Manufacturers and users
can leave general information or specific
details concerning special personal-
computer equipment specifically in-
tended for the disabled. Also, through the
Texas Instruments Texnet tie-in with The
Source, the UPI news service is prepared
for voice output through a personal com-
puter with a speech synthesizer. (Got the
idea of what we’re looking for? We want
everything in communications for the dis-
abled!)

If you have any specific knowledge
about personal-computer or com-
munications equipment that would bene-
fit the disabled — such as a moderately
priced Braille printer for the Apple com-
puter, or a store-and-forward with voice
output for any personal computer — put it

up on The Source or pass it along to me
here.

Saving money by telephone

The way I heard it a few years ago, the
telephone was dead. Microprocessors,
satellites, and systems that we hadn’t
even yet conceived were going to make
the telephone system as obsolete as the
singing telegram. Well, here it is a few
years into the computer age and the tele-
phone is livelier than ever thanks to new
developments. We’re getting more low-
cost telephone systems than we could
imagine, all thanks to the computer,
microwave communications, satellites,
and whatever new inventions our engine-
ers will conjure up in the coming years.

Just as soon as I finish typing this col-
umn I am going to telephone the editor
and explain why it’s late. It’s a call in the
same part of the state, but it will cost a lot
less than usual. I will press two keys on
the keypad built into the mouthpiece of
my phone, and a computer also built into
the mouthpiece will dial Sprint. Sprint is
one of several communications services
that provide short- and long-distance tele-
phone service that is less expensive than
the equivalent service from the telephone
company (which we’ll call Telco). When
I hear the Sprint answer-tone, I will press
two more keys, and the mouthpiece com-
puter will transmit my identification,
travel code (which I can use from coast to
coast), and the number that I’m calling. A
Sprint computer will recognize who I am
and route my call though its facilities to
New York City, put it back into the Telco
system, and connect my call. I will be
billed by Sprint, and pay about 40% less
than I would for a telephone call made in
the standard way. My only extra charge
will be the local one for the connection to
Sprint.

As you might guess, the secret to all
that is a computer that does the Telco-
system interconnects and the monthly
billing. There are several ways that such a
communications system can be put
together, so we’ll construct a “basic”
model that will help you understand this
new wrinkle that’s shown up in telephone
communications.

First, it’s possible to purchase “bulk”
telephone service from Ma Bell at lower
rates than regular subscribers pay. Then,
there are private and public microwave
systems through the main business corri-

SEE YOUR DEALER TODAY

SAVE!

MONEY * TIME • FREIGHT

L, QUALITY STEREO EQUIPMENT
P AT LOWEST PRICES.

L' YOUR REQUEST FOR QUOTA-
P TION RETURNED SAME DAY.

L' FACTORY SEALED CARTONS—
P GUARANTEED AND INSURED.

it SAVE ON NAME BRANDS LIKE:

PIONEER

KENWOOD

MARANTZ

TECHNICS

JVC

TEAC

SANSUI

SONY

AND MORE THAN 50 OTHERS
BUY THE MODERN WAY
BY MAIL -FROM

..BO.

iliAoS^wdio

BANK CARDS ACCEPTED

12 East Delaware
Chicago, Illinois 6061 1
^ 312-664-0020 .

8no -R9i-«n49

CIRCLE 94 ON FREE INFORMATION CARD

For Home or Business
WHAT. ..WHEN. ..HOW...

BE A

COMPUTER

PROGRAMMER

Train at home in spare time! No
previous experience needed! Now
you can learn it all! Com-
puter programming. ..compu-
ter applications.. .computer
games. ..everything you ever
wanted to know about com-
puter operations! Write your
own computer programs or
use hundreds of programs
already available. ..budget-
ing, real estate, bookkeep-
ing, expenses, investments,
interest, taxes, shopping
lists, vacation planning,
addresses, phone num-
bers, routing ...even
foreign languages and
graphics.

You’ll know what really happens when you have a com-
puter problem with a bank, store, loan company, oil
company, utility or anyone else. You’ll be able to talk
their language. ..understand why and how things hap-
pen.. .to be able to take the offensive when you’re the
victim of a computer error. Experts explain everything
in easy-to-understand language with step-by-step
directions.

• TIMEX COMPUTER INCLUDED WITH
YOUR TRAINING • Plugs into any TV

ICS

> SEND F0R_FR_E£_FACTS!

COMPUTER TRAINING, Dept. DE063 -

Scranton, Pennsylvania 18515

Please rush me free facts and color brochure i
that tells how I can learn computer applications, J
programming and operation at home in spare |
time. No cost. No obligation.!

Name Age ■

Address ■

I City/State/Zip ■

dors, such as New York to Atlanta, or Los
Angeles to Chicago, or Houston to every-
where. Since communications circuits
are often kicked upstairs to a satellite (be-
cause its easier to get over a mountain that
way) , it’s a safe bet that part of our budget
communications will involve satellite
transmission (as is often the case with
“regular” telephone service).

Figure 1 shows how a hypothetical sys-
tem we’ll call “Com-Fone” might be
used to provide you with low-cost tele-
phone communications. Starting at point
“A,” you use your standard phone with
rotary or Touch-Tone dialing to get into
the nearest Com-Fone node (switching
center). Com-Fone’ s computer answers,
and on hearing the answer tone, you
transmit your identification code using
Touch-Tone frequencies. You cannot use
the standard telephone dial pulses be-
cause the Com-Fone computer “un-
derstands” only the DTMF (Dual-Lone
Multi-Frequency) tones used by the
Touch-Tone system. Still using tones,
you dial the area code and number you
want. The computer checks your I.D. If
it’s not valid, the computer does an in-
tercept and a computerized voice informs
you that that’s the case. If your account is
clear, the computer seizes an open com-
munications path that may be part micro-
wave link, part satellite, and part Ma Be-
ll’s wiring. At the receiving end, the com-
puter connects back into Ma Bell’s sys-
tem and dials the local telephone number
that you are trying to reach.

You pay the telephone charge (to your
local telephone company) from your
phone to the Com-Fone node. Com-
Fone’ s computer calculates and bills you
for the charges for service from the node
right up to the party you called. Com-
Fone ’s costs (what Com-Fone must pay
Ma Bell) at the receiving end— where
your call re-enters Ma Bell’s wiring — are
calculated and built into your Com-Fone
charges. But because Com-Fone pur-
chases bulk telephone-service, your total
bill is reduced.

Oh yes! That computer inside the tele-
phone mouthpiece! That’s not hypothe-
tical, it’s a Soft-Touch dialer from Bus-
corn Systems, Inc. (4700 Patrick Henry
Drive, Santa Clara, CA 95050) that pro-
vides Touch-Tone dialing on rotary dial
telephones. It substitutes a microphone
and miniature keypad for the existing car-
bon microphone . It has 80 programmable
memories that are accessed by pushing
two buttons. The memories are main-
tained by subminature batteries that last
several years. The memories stack auto-
matically, so you can program any series
of access numbers and codes; all of them
are transmitted by pressing the two but-
tons representing the initial memory ad-
dress.

Next month, when we continue, we
will look more closely at that Touch-Tone
autodialer. We’ll also be looking at other
applications for Touch-Tones. R-E

FROM

Tirestik’

•ANTENNAS*
• ACCESSORIES *

HERE’S A TIP
THAT’S PERFECT!

AM/FM AUTO RADIO
AND CB

‘Firestik’n

GOLDEN SERIES

BARE-HANDS TUNABLE
“NO TOOLS NEEDED”

HIGH PERFORMANCE ANTENNAS

ALSO ANTENNAS FOR
CORDLESS TELEPHONES
MONITOR SCANNERS

Dealer & Distributor Inquiries Invited
SEND FOR FREE CATALOG

Firastik' Antenna Company

2614 East Adams/Phoenix, AZ 85034

Street _
City _

- Zip _

Serving the CB and
Communications Market Since 1962.

5-YEAR REPLACEMENT WARRANTY

CIRCLE 40 ON FREE INFORMATION CARD

(inker Iron

MINI POWER SUPPLIES’

'5 Models •100mA to 3.0 A *1.5 to 20 Volts

Pmodel

VOLTAGE

DIGITAL

DISPLAY

AMP

ADJ

CURRENT

PRICE

1530A

1.2— 15V

Yes

3 Amp

$216.00

20 20 A

1.2— 20V

Yes

2 Amp

179.95

0530A

Yes

3 Amp

149.95

1230B

12V

Yes

No '

3 Amp

149.95

1295B

5. 9. 12V

No |

100mA

69.95

The Phaser II (Model P-2280)

Infrared Transmitter and Receiver Switch

* Turn Appliances On/Off

* Range Up to 30’ $OQ95

* Switch Handles 500 Watts

* Directional (Just Point)

Magic Touch Ceiling Fan/Light Control

* Works on any Fan/Light

* No Additional Wiring $QQ95

* Controls Fan Speed/Light Brightness ^

* Eliminates Motor Hum (Not Triac)

This new concept totally simplifies ceiling fan installation Just
remove light fixture and switch, and replace with your fan and
the Magic Touch control system. With no addition to your
existing wiring, you can control fan speed and light brightness.

Encapsulated Modules for PCB Mount

(Application notes included)

Z500 AUDIO AMPLIFIER — 4-1 2V operation, 4mA quiesent
current, output 500mW with 9V supply and 8 ohm speaker.
Requires only a speaker and 10K pot. $6.95 3/$18.00

Z100 PREAMP — (for additional amplification) $5.95

DC to DC Polarity Converters

Generate negative output from positive input voltage

Solid State Relays

Send 25c for our 1983 Summer Catalog of electronic parts (free, with order)
including resistors, capacitors, semiconductors, plastic boxes, motors, etc.

LOWEST PRICES — SAVE UP TO 50% OR MORE!

Add $2.00 shipping to each order. In Texas add 4% tax. $10.00 minimum order.

WS4

I inker Iron

P. O. BOX 53128
LUBBOCK, TEXAS 79453
806/745-2228

All TinkerTron Products Have A Ten Day Money-Back Trial Period.

CIRCLE 30 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

USING LORANC ETC.

continued from page 67

idea of using Loran-C for frequency-
standard checking/calibration. The GRI
source, driven from a local frequency
standard, is used to trigger the scope ex-
ternally. The Loran-C signal, either from
a suitable receiver or from the RF front
end (the circuit shown in Fig. 7) is dis-
played, and the sweep time is adjusted to
observe some part of a particular signal.
The Loran-C signal at a given GRI can be
momentarily speeded up or slowed down
by “bumping” the thumbwheel switches
of the GRI generator to place the Loran-C
trace at some point on the scope so that a
very small part of the leading edge of a
pulse can be observed. Then, by de-
termining the length of time it takes the
Loran-C signal to move a given distance
across the screen of the scope, the frac-
tional frequency-stability of the local 1-
MHz standard can be determined.

How is that time measurement used to
obtain a measurement of the relative fre-
quency stability? The two measurements
can be related by calculus; we will only
give the result: A f/f = -At/T.

Here, At is the change in time (the
drift) read over a measurement time, T.

If, for example, the result was 1.5 x
10 _6 , it would indicate that the oscilla-
tor’s actual frequency was its nominal
frequency (in this case 1 MHz) multiplied
by 1.5 X 10 -6 . In this case, the actual
frequency of the standard would be
1.0000015 MHz. Typically, with a good
(proportional oven controlled) standard,
the Loran-C signal will only move to the
right or left about 10 ps/hom. That impl-
ies an offset of the order of 3 x 10 -9 .

The expanded scope-trace (about 10
^/division) is useful for examining the
actual RF-carrier output from the pin-1 1
test point of the MCI 357 detector in Fig.

7. The envelope of that signal at the out-
put of the op-amp-filter can also be
observed, and the movement of the in-
flection point or zero crossing can be re-
corded at hourly intervals to check the
clock-stability.

When using receivers like the

zm & T.'S 1000 CATALOG

I Use the convenient coupon
below and send for your FREE
catalog TODAY!

New from Gladstone
Electronics! OurZX8l/
TS1000 catalog will
take you where no one
has dared go before !
You will view the
widest selection of up-
to-date software, books
and hardware add-ons
available to get the
most from your
personal computer.
This exciting new 34
page color catalog lists
arcade, fantasy and
family games, business
and educational
programs; books for
beginners as well as
experienced users;
hardware add-ons and
other peripherals for
use with ZX81/TS1000
Home Computer!

GL3DSTOHE Ele ' “

Please rush me this exciting new ZX81/TS1000 catalog.

City State Zip

Mail to: 1 585 Kenmore Ave., Buffalo, N. Y. 1 421 7
In Canada: 1736 Avenue Rd., Toronto, Ont. M5M 3Y7

Put Professional Knowledge and a

COLLEGE DEGREE

in your Electronics Career through

HOME #5* 0i
STUDY .JSL®

Earn Your

DEGREE

No commuting to class. Study at your
own pace, while continuing your present
job. Learn from easy-to-understand les-
sons, with help from your home-study
instructors whenever you need it.

In the Grantham electronics program,
you first earn your A.S.E.T. degree, and
then your B.S.E.T. These degrees are ac-
credited by the Accrediting Commission
of the National Home Study Council.

Our free bulletin gives full details of
the home-study program, the degrees
awarded, and the requirements for each
degree. Write for Bulletin R-83.
Grantham College of Engineering
2500 So. LaCienega Blvd.

Los Angeles, California 90034

FRG7700 for Loran-C, the envelope rise-
time is smeared out over 150 ps or so. But
by observing the change of that signal at
daily time intervals, with the clock and
GRI source operating continuously, the
frequency stability of the clock can be
determined without any special Loran-C
front-end hardware.

For Loran-C DX hunting on late winter
evenings when the noise level is low and
DX is coming in from other stations such
as Allouis in France on 164 kHz, the GRI
rate can be set to try to find some chain not
normally observed in the USA. That is
done by examining the whole GRI frame
in detail (with the oscilloscope in the
expanded-sweep mode) and slowly
bumping the GRI rate a few tens of mil-
liseconds at a time to find weaker sky-
wave pulses standing still. Loran-C sig-
nals from the USSR using GRI rates of
8000 and 5000 can sometimes (although
rarely) be observed that way. The main
problem in looking for weak signals is the
cross-rate interference from other chains
drifting by the desired small-amplitude
signal on the scope trace.

A photograph of an experimental mod-
el of a Loran-C RF-envelope detector is
shown in Fig. 10. Circuit-board layouts
have been prepared for the Loran-C RF
detector and the GRI generator. Contact:
R. W. Burhans, 161 Grosvenor St.,
Athens, Ohio 45701 . Include a SASE for
information on the availability of these
boards for experimental use. R-E

ON SALE

AT YOUR

LOCAL

NEWSSTAND

JUNE 2

Reserve your
copy now!

Get every issue

TODAY!

Use the order
form below

Special Projects #7

■ IF YOU’RE THE KIND OF READER
that doesn’t want to wait, you can get
your copy of Special Projects #7 now.
This 100-page magazine is crammed
full of electronic projects that you won’t
be able to wait to build for yourself.
There’s a Digital Prototyping System, a
Soundbox to add sound to TRS-80
games, a Code-Practice Oscillator,
Electronic Flasher for your car, plus all
the other articles listed on the cover
above. You get a total of 21 fun-filled
build-it stories.

■ TO HELP YOU TO BE SURE that
you don’t miss any future issues —
SUBSCRIPTIONS ARE NOW AVAIL-
ABLE!

■ YOU CAN HAVE THE NEXT FOUR
ISSUES of Special Projects delivered
directly to your home for only $9.00. We
pay the postage. If you want the next
eight issues, you can even save a dollar
off the newsstand price. Get eight issues
for $17.00.

■ EVERY ISSUE OF SPECIAL PROJ-
ECTS will continue to contain a variety
of construction articles to suit every
taste. In addition, feature articles on
electronics fundamentals, test equip-
ment and tools will round out each issue.
Of course, we will continue to provide
new product and literature listings to
keep you up to date on the latest de-
velopments in electronic technology.

■ GET IN ON THE ACTION! Order
your next issue of Special Projects to-
day. Use the convenient order coupon
below.

CASH WITH ORDER ONLY RE-7

Allow 6-8 weeks for the first issue to arrive.

Please print

(Name)

(Street Address)

(City)

(State)

(Zip)

Special
Projects #7

□ Send me

DETACH AND MAIL TODAY TO:
SPECIAL PROJECTS
SUBSCRIPTION DEPT.

200 PARK AVE. SOUTH
NEW YORK, N.Y. 10003

-copies of Special Projects #7

at S2.25 plus $1 .00 postage and handling for US, Canada and Mexico.
U.S. funds only. All others add $2.00.

i 1 I want to be sure I don't miss any issues. Send me the next four issues
of Special Projects for $9.00: starting with #7. Postage is free in U.S.
For Canada add $3.00. Foreign add $7.00.

□ I want to be sure I don't miss any issues and want to save $1 .00 too.
Send me the next eight issues of Special Projects for $1 7.00: Starting
with #7. Postage is free in U.S. For Canada add $6.00. Foreign add
SI 4.00.

RADIO-ELECTRONICS

ANALOG CIRCUITS

continued from page 72

complex passive- and active-circuits
around an op-amp. A triangular wave can
be formed by adding the op-amp in-
tegrator shown in Fig. 13 to the output
terminals of a squarewave generator like
the one shown in Fig. 12.

Among the most popular oscillator cir-
cuits is the Wien bridge. A basic transis-
tor circuit using the Wien bridge is shown
in Fig. 14. Here, the Wien bridge circuit
is placed around a single-ended differen-
tial amplifier; it consists of the series and
parallel-connected R-C networks. Cur-
rent is fed back through that filter network
from the output to the input. Oscillation

FIG. 13— AN INTEGRATOR, such as the one
shown here, can be used to change a square-
wave into a triangular wave.

occurs if the forward gain of the amplifier
is greater than 3 because the output at the
junction of the series and parallel R-C
circuits is Vs of that at the collector of Q2.
The frequency of oscillation is 1/
2 jcR 1C1, assuming that R1 =R2andCl
= C2.

A similar circuit can be built around an
op-amp, as shown in Fig. 15. Positive
feedback is applied through the R-C Wien
bridge to the non-inverting input of the
op-amp. Negative feedback is applied
through a resistor divider to the inverting
input. The frequency of oscillation is
found exactly as it was in the previous
example. Two Zener diodes are included

+v cc

FIG. 14— ONE OF THE MOST POPULAR sine-
wave generators, the Wien-bridge circuit has
been around since the days of vacuum tubes.

FIG. 15— ANOTHER EXAMPLE of the Wien
bridge, this one is built around an op-amp.

in the circuit to keep the output voltage,
when at a peak, from putting the op-amp
circuit into saturation. If it did go into
saturation, the circuit would remain in
that state and oscillation would no longer
take place.

High frequency

Unwanted feedback is quite likely to
occur in high-frequency circuits. It has
many causes: To give just one example,
signal at an output can be coupled back to
the input through adjacent wiring or
through stray capacitances in a circuit. In
the next article in this series, we will
explore and determine just what its effects
are and how to handle them in transistor
circuits. R-E

TAFT

ELECTRONIC

SALES

HAS IT ALL FOR LESS

NORTH

AMERICAN

•MS-3015-15MHZ
DUAL TRACE PORTABLE
• MS-6020-20MHZ
DUAL TRACE
•MS-6035-35MHZ
DUAL TRACE
•MS-6050-50MHZ
DUAL TRACE
•MS-6100-100MHZ
QUAD TRACE

CALL FOR LOW,

LOW PRICES

DIGITAL MULTIMETERS

IflukeI

• 8060A $345

• 8062A $275

• 8022B $143

• 8020B $193

• 8024B $247

BECKMAIM

• 300 $109

• 310 $129

• 330 $199

Xcelite®

TC-100ST
XCELITE’S BEST
CONTAINS 53 TOOLS

$329

TC-150ST
SMALLER UNIT
CONTAINS 23 TOOLS

$279

• 1476P-10MHZ

DUAL TRACE $439

• 1477P-15MHZ

DUAL TRACE $495

• 1479BP-30MHZ
DUAL TRACE $609

• 1570P-70MHZ
QUAD TRACE $1079

PRICES INCLUDE PROBES

6.5MHZ OSCILLOSCOPE AT ONLY

$ 188.00

•6.5MHZ

•75MM ROUND SCREEN
•lOmV/DIV. SENSITIVITY
•INTERNAL OR EXTERNAL SYNC
•XY VECT0RSC0PE CAPABILITIES
• 8 V 2 LBS. LIGHT & COMPACT
•OUTPERFORMS UNITS COSTING
MUCH MORE

ONE-YEAR WARRANTY

20,000 OHM/VDC V-0-M

• DC/AC VOLT TO
1 KV

•FUSE & DIODE
PROTECTION
•17 RANGES ON
MIRROR SCALE
•LEVER SELECTOR
RANGE SWITCH

$ 19.88 ONE-YEAR WARRANTY

VIDEO CONTROL CENTER

46 CHANNEL VCR

} L __ ^ ■

CONVERTER WITH

jgpi pi 1

FINE TUNING $ 27.88

jgjg^ ti6 ' 88

" ” 1 ’

REMOTE CONTROL ACCESS

■W { H"™" -)

OF ALL VIDEO, TV OR CABLE

INPUTS TO TV SET.

WATCH ONE CHANNEL

4 INPUTS TO ONE OUTPUT

AND RECORD ANOTHER

STABILIZER/VIDEO FADER/
ENHANCER/RF CONVERTER

TAFT ELECTRONIC SALES

CALL

• MASTER CHARGE • VISA

68 W. 45th Street

212-575-

• MONEY ORDER • CHECK

N.Y.C., N.Y. 10036

8632

25% DEPOSIT ON C.O.D.’s

$ 99.88

ONE UNIT DOES IT ALL

ADD FOR SHIPPING
UP TO $300.00 • $5.50
OVER $300.00 • $8.00
N.Y.S. ADD SALES TAX

CIRCLE 38 ON FREE INFORMATION CARD

NEW BOOKS

For more details use the free information card inside the back cover

MY INVENTIONS, The Autobiography of
Nikola Tesla (Introduction by Ben John-
ston); Hart Brothers, Publishing, PO Box
205, Williston, VT 05495; 112 pp., illus-
trated; 5V 2 x 8 V 2 inches; softcover; $7.95;
hardcover $12.95.

This material by the great Yugoslav-
American inventor (1856-1 943) has been vir-
tually unavailable since 1919 when it was
published serially in Hugo Gernsback’s Elec-
trical Experimenter. The editor’s note tells us
that Tesla’s ‘‘idiosyncratic phonetic spell-
ings” have not been changed in this edition,
but some of the picture captions have been
revised. All the original illustrations are here,
and six new ones have been added. There
are two excellent wash illustrations by Frank
R. Paul, who later became world-famous as
the principal illustrator for the Gernsback sci-
ence fiction magazines.

Tesla was 63 when these articles were
published; they reveal his youthful struggle to
harness his runaway imagination; after the
chapters ‘‘My Early Life,” and ‘‘My First
Efforts in Invention”, we proceed to the dis-
covery of the rotating magnetic field, the Tes-
la coil and transformer, the magnifying
transmitter, and the art of teleautomatics.
Much of what the reader may have seen in
various biographies is a mixture of fact and
fiction; here the inventor himself sets the rec-
ord straight.

Although he lived and worked in the United
States for nearly 60 years, by the time he died
he was virtually forgotten. The present
volume is needed to bring Nikola Tesla into
proper perspective.

CIRCLE 121 ON FREE INFORMATION CARD

MICROCOMPUTER EXPERIMENTATION
WITH THE MOS TECHNOLOGY KIM-1, by
Lance A. Leventhal; Prentice-Hall, Inc, En-
glewood Cliffs, NJ 07632; 467 pp., includ-
ing appendices and index; 6 % x 9V4 inch-
es; softcover; $16.95.

This practical easy-to-follow and self-
contained guide to MOS Technology KIM-1
experiments represents diverse disciplines
and a wide variety of applications. The em-
phasis throughout is on approaches that are
fundamental to the design of controllers for
exernal systems; at the same time, it illus-
trates its points through examples that use
nothing more complex than switches, single
displays, and the on-board peripherals.

The inexpensive and widely available KIM-
1 microcomputer and 6502 microprocessor
were selected to provide realistic experience
with popular devices for those involved in a
wide range of control-operation applications:
instrumentation, communications equip-
ment, test equipment, computer peripherals,
industrial processes, signal processing, busi-
ness equipment, consumer products, and
many more.

There are two major groupings of ex-
periments. Those in the first group focus on
writing and running simple programs, simple
input and output, processing of inputs and
outputs, forming and processing data arrays,
designing and debugging programs, and
arithmetical operations. Those in the second
group deal with subroutines and the stack,
input/output using handshakes, interrupts,
timing methods, serial input/output, and
microcomputer timing and control.

CIRCLE 122 ON FREE INFORMATION CARD

70 YEARS OF RADIO TUBES AND
VALVES, by John W. Stokes; The Vestal
Press, Ltd., PO Box 97, Vestal, New York
13850. 256 pp., including glossary and in-
dex; 8V2 x 11 inches; hardcover; $21.95
through bookstores— add $ 2.00 shipping
when ordering from publisher, and New
York residents add 7% sales tax.

Here is the history of the radio tube from its
invention in 1 904 to its gradual eclipse, begin-
ning in the 1960’s when it was replaced by
solid-state devices. The emphasis, however,
is on developments occurring between 1927
and 1937 — the period when the “all electric”
receiver evolved to become a familiar part of
our daily lives.

All the giants of the industry —
Westinghouston, General Electric, Sylvania,
RCA, Raytheon, and others their size, as well
as many smaller firms now forgotten — are
covered in this story of how our technical
know-how progressed in the period. It ranges
from Edison’s discovery that electrons would
flow in a vacuum (the “Edison effect”) to Lee
deForest’s invention of the “grid”, to RCA’s
“Nuvistor” that closed the era.

CIRCLE 123 ON FREE INFORMATION CARD

A MANAGER S GUIDE TO INDUSTRIAL
ROBOTS, by Ken Susnjara; Corinthian
Press, publishing division of EDR
Corporation, Shaker Heights, OH; 181 pp.,
including appendices, but no index; 6Vs x
8 V 4 inches; hardcover; $24.95.

The robot industry is one of the fastest-
growing industries. The capability of those
machines, the number of units available, the
number of manufacturers, and the number of
installations, are all growing at an astounding
pace.

This book discusses the new technology in
a simple, straightforward manner. It is de-
signed for the non-technical manager who
must deal with robots, and assumes no pre-
vious knowledge or experience in the area on
the reader’s part. The author addresses such
questions as: “What is an industrial robot?”;
“How do industrial robots works?”; “What
can they do and what can they not do?”;
“How much do they cost?”; “How do I find
applications in my plant?”, and “How do I
handle labor and community relations?”

This illustrated, comprehensive guide in-
cludes a reference manual covering the de-
tails of installing and using an industrial robot.

It also provides a glossary of robotic and tech-
nical terms explained in simple, non-
technical language.

CIRCLE 124 ON FREE INFORMATION CARD

THE ILLUSTRATED DICTIONARY OF
ELECTRONICS (2nd Edition), by Rufus P.
Turner; TAB Books, Inc., Blue Ridge Sum-
mit, PA 17214; 893 pp.; 5V2 x 8V4 inches;
softcover; $16.95.

Anyone in any way associated with the
electronics field, whether beginning hobbyist,
experienced, amateur, or professional will
find this book valuable. From ‘‘A” to
“zymurgy”, the more than 25,000 definitions
provide needed information to anyone who
wants to look up an electronics term in a
hurry. The new 2nd edition has not only been
completely updated, but contains over 600
new entries, covering electronics, radio, au-
dio, computers, and related studies.

In addition to the alphabetically-arranged
definitions, there is a “Tables and Data”
appendix that includes the resistor color
code, electronics symbols, wire guage,
abbreviations, and a variety of conversion
tables.

CIRCLE 125 ON FREE INFORMATION CARD

THE BASIC HANDBOOK (2nd edition),
Encyclopedia of the BASIC Computer
Language, by David A. Lien; Compusoft
Publishing, San Diego, CA 92119; 480 pp,
7x9 inches; softcover; $19.95.

The BASIC language has changed in many
ways since 1 978, when the first edition of this
book appeared. With each new computer
came new words, and with each new word
the need to update. Drawing upon his exten-
sive BASIC language library, and with the
assistance of many manufacturers, the au-
thor has attempted to document and explain
virtually every BASIC feature of every type of
computer in the world.

Special attention has been given to
documenting the diverse BASICS im-
plemented on the many new computers in-
troduced (and about to be introduced) from
Europe and Asia. In addition to filling gaps in
the 1 st edition, a strong effort has been made
to continue documenting ‘‘disk BASIC”,
which many users find frustrating. Although
there are as yet no standards for “disk
BASIC’s,” only common concepts, the
documentation follows those trends that can
be identified.

This new second edition introduces 238
additional words, bringing the total of BASIC
words to almost 500. Nearly every significant
BASIC word, used by virtually every BASIC-
speaking computer in the world is explained.
CIRCLE 126 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

mm mm mmm mmm mm imms t

* Im**ri*tpettp

* ii tm&M* K h*x eetm

§ m m»Mim pm pimtm mm iieplm
m m tm mmk&k kp&m$

i mim tN&m*

* MmsH MK m $r« 52

i iNStir U miWrnmm

* 9 mM ilrnimm
i UrtSfr MQC lap**

Full size smart terminal with detachable keyboard

4Mhz Z80A CPU

64K RAM Main Memory

200Kbyte 514" floppy disk '

(Osborn, Xerox, IBM, CP/M-86 formats)
Two serial ports

Complete software package includes:
WordStar word processing
Correct-lt spelling checker
LogiCalc electronic spreadsheet
Microsoft BASIC
NorthStar compatible BAZIC
CP/M 2.2 Operating System

CIRCLE 77 ON FREE INFORMATION CARD

At $1790, this computer was selling like
hotcakes. So we dropped the price.

Crazy? No, not really. You see in order to meet the
demand for the Micro Decision™ we increased our
production. When we did that our costs dropped. We're
passing our savings on to you, because that's our
philosophy.

More for less.

So now it only takes $1590 to buy a Micro Decision with
64K of memory, a 200K double-density floppy drive and
a full-size Morrow smart terminal with detachable key-
board. Not bad. But there's more.

The Micro Decision also includes a package of business
and professional software worth well over $2000. The
WordStar® word processor. A 36,000 word spelling
checker. The LogiCalc™ electronic spreadsheet. And both
Microsoft BASlC-80® and NorthStar-compatible BAZIC?
Plus, the CP/M® 2.2 Operating System that gives you
access to thousands of other software programs. And,
we take the mystery out of CP/M with plain English
commands and single-key operation.

If you have your own terminal, you can buy the complete
computer and software package for $995. That's the
Micro Decision MD1™ The MD2™ includes another
double-density disk drive, plus Personal PEARL™ the
relational data base manager. Price? Only $1395.

More memory? No problem. The Micro Decision MD3™
gives you two double-sided, double-density disk drives
with 768K of storage and Personal PEARL for only
$2490. Without the terminal, $1895.

Come in for a complete demonstration at your nearest
Morrow dealer. If you don't know who that is, call us
toll-free at (800) 521-3493. In California, call (415) 430-
1970. At $1790, the Micro Decision sold like hotcakes.
At $1590, we've just sweetened the deal.

MORROW

MORROW, 600 McCormick Street San Leandro, CA 94577
(800) 521-3493, (415) 430-1970 In California

CIRCLE 77 ON FREE INFORMATION CARD

JULY 1983

§ RADIO-ELECTRONICS

MASTERING
MICROPROCESSORS
BEGIN WITH LS6802

LS6802 is a complete learning system to master
microprocessor hardware and software. It is based on
the 6802 CPU, an improved version of the renowned
6800 and is a good starting point to master the varieties
of 6800 family microprocessors so widely used in indus-
try.

Its features include: 2K monitor program with 20 edit-
ing, debugging functions; 2K RAM; spare socket for 2K
RAM or 4K EPROM; built-in breadboarding system for
hardware experiments; speaker; cassette tape in-
terface; 16 programmable I/O lines (6821 PIA); 3 user
keys; the full capabilities of 6802 CPU and an AC/DC
adaptor to power the LS. An ideal tool for learning,
teaching, experimenting and prototyping at only
$159.00. 90 days warranty.

Binary System, Maxwell Road, P.O. Box 1583,
Singapore 9031 , Republic of Singapore.

Send me unit(s) of LS6802 at $1 59.00 each, a total
amount of . I am paying by Money

order, Visa, Mastercard American Ex-
press.

Name

Signature

Address —

Card No Expires.

CANCER.
NOT KNOWING
THE

RISKS IS YOUR
GREATEST RISK.

A lot of people think cancer
is unbeatable.

That simply isn’t true. In fact,
over two million people have had
cancer and survived to lead
happy, normal lives.

And not only can cancer be
beaten, it can also be prevented.

There are definite precau-
tions that have been proven to
decrease your risk of getting cer-
tain cancers.

Ask your local American
Cancer Society to send you a free
booklet about cancer risks.

Learn the facts about cancer.

And make not knowing the
| risks, one less risk.

& AMERICAN CANCER SOCIETY;

" How you live may save your life.

This space contributed as a public service.

Electronics. You deserve it!
Get it every month

Come on, treat yourself... save up
to $10.03 off the newsstand price.

Subscribe to RADIO-ELECTRONICS and have
the best electronics magazine delivered
to your home — check off the money-saving
offer you prefer on the handy coupon, and
start enjoying RADIO-ELECTRONICS every month.

Enclose your payment and get ONE EXTRA ISSUE per year.

Get the Best — Every Month! Mail Today!
YES! please send me

7HG33

| □ Payment enclosed, 13 issues $14.97 □

■ (You save $4.53 off newsstand price.)

■ Canada $17.97 - U.S. funds only

■ □ Payment enclosed, 26 issues $28.97 □

| (Save More! $10.03 off newsstand price)

i Canada $34.97 - U.S. funds only

I Name

Bill me * 12 issues $14.97

(You save $3.03 off newsstand price.)
Canada $17.97 - U.S. funds only

Bill me - 24 issues $28.97

(Save More! $7.03 off newsstand price.)
Canada $34.97 - U.S. funds only

(please print)

Address-

City

Mail to: RADIO-ELECTRONICS
RO. Box 2520
Boulder, Colorado 80322

State-

Zip Code-

Offer valid in U.S. and Canada only
Allow 6-8 weeks for delivery of first issue.

EQUIPMENT REPORTS

continued from page 38

in the ohms range and have come back to
it only to find a dead battery. Of course
my multimeter didn’t have a separate
power switch.) Across from the power
switch is a transistor test socket. Four
input-jacks (v-O, com, mA, and 10A) are
in a row across the bottom, below the
range selector. The readout is a ‘ ‘bright, ’ ’
easy-to-read, 3 VTdigit LCD display that
includes a low-battery indicator.

The 8050 has thirty ranges that cover
eight functions. It can measure DC vol-
tages to 1000 volts over five ranges (200
mV , 2 volts , 20 volts , 200 volts , and 1 000
volts), and AC voltages to 750 volts over
similar ranges (except for the upper
limit). The input impedance is 10
megohms on all voltage ranges. AC and
DC current can be measured to 10
amperes over five ranges: 200 /xA, 2 mA,
20 mA, 200 mA, and 10 amperes. (The
10-amp range requires that a separate in-
put jack be used.) Polarity indication is
automatic, with a minus sign appearing at
the left of the display. And if the battery is
low, an arrow appears on the left of the
readout.

Resistance measurements (with auto-
matic zeroing) can be made to 20
megohms over six ranges: 200 ohms, 2K,
20K, 200K, 2 megohms, and 20
megohms. Those resistance measure-
ments are accurate to within 1% of the
reading on all but the 20-megohm range,
where the accuracy 2%.

Other features

A separate position on the range-
selector switch, marked with a diode
symbol, lets you quickly check diodes.
There is also an audible continuity-test
position. It sounds rather shrill, but it’s
very handy for making quick continuity
checks.

One unusual feature that is included on
the 8050 is a test socket at the upper right
of the panel that lets you find a transistor’ s
hFE (Beta) on a 0 to 1000 scale. The
npn-pnp positions on the range switch
select the type under test — or they can be
used to identify an unknown transistor
type. Maximum collector-to-emitter volt-
age is 2.8 volts under test.

This little instrument is very con-
venient easy to use. All controls are easy
to get at, the readout is visible under all
practical conditions, and it is compact
enough to fit into the average work-shirt
pocket. It’s also magnetically shielded;
the manufacturer claims that even strong
magnetic fields will not affect its accura-
cy. The test leads that come with it have
nice sharply pointed tips that can make
some measurements much easier. All in
all , the 8050 is a lot of meter for its $89.95
price. R-E

SERVICE QUESTIONS

continued from page 83

voltage at the pin to be 1 8 volts. Installing
a 14.2K resistor between pin 24 and pin
29 (ground) pulled that voltage down to
14.5, and restored proper clock operation
in all modes. The value of the resistor was
found experimentally. Incidently, if you
need a new clock IC, they can be bought
from SSI Components Ltd., Suite 201,
Austin Centre, 21 Austin Ave., Kow-
loon, Hong Kong. They cost $1 1 .00 each
(in U.S. funds) when bought in quantities
of 1 to 24. — V.M., Bronx, NY

BURNING CAPACITOR

After fixing some other problems in this
Zenith 23 EC 15, 1 noticed a burning smell,
but no smoke, coming from the set during
testing. When I investigated I found that
fuse F204 had blown, and that capacitor
C267 had burned to a crisp. Replacing the
fuse and capacitor got the set working,
but after an hour the capacitor began get-
ting hot again. What's going on here?—
B.M., S. Portsmouth, KY

What you’re describing is fairly com-
mon in solid-state sets, although this is
the first time I’ve ever heard about it in a
tube set. In any event, the cure should be
the same. Capacitor C267 is in a circuit
with horizontal-frequency pulses; an
ordinary capacitor won’t work there. You
need one of the special “RF” types, one
with dielectrics rated to handle the high
frequency. Either get an exact Zenith
replacement, or one rated for high-
frequency service.

UNUSUAL VERTICAL PROBLEM

I had a vertical problem in a Zenith
13A16Z. You made several suggestions
including checking the resistance of the
vertical-output transformer’s primary.
After following all of your other hints,
and replacing several bad components
that I had found, the problem was still
there. When I did get around to checking
that transformer, the primary’s resistance
was indeed lower than it should have
been. Replacing the transformer solved
the problem. — A.S., Middletown, NJ

Glad to hear that you found it. Failure
in those transformers is really quite rare,
but, as you discovered, it can happen.

PEGGING METER

The meter needle on this tube-type
VTVM pegs to the right side. I’ve heard
about pegging to the left, but never this.
What’s going on?— AM., Darlington, MD

If the meter pegs in either direction, it
means that there is a bad unbalance in the
circuit. Most often, the cause is a de-
fective VTVM bridge tube, usually a
12AT7 or similar twin triode. Note that
you may need to try several tubes, es-
pecially in the older models, before you’ll

find one that will balance the circuit.

Feedback — That was the problem;
only needed to try one tube before the
trouble cleared up.

COLLAPSING RASTER

I’ve run into a problem that seems to be
common in the Zenith System-3 sets that
use the 9-153 high-voltage module. The
symptom is an intermittent collapse of the
raster and horizontal foldover. The cause
is poor solder-connections on two com-
ponents: the horizontal-output transfor-
mer and T3301. It helps to take those
components out, scrape the connections
clean, and then reinstall them. I’ve seen
that problem in six sets over the past few
months, including my own. — George
Yarbrough, West Yellowstone, MT

CREEPING HIGH VOLTAGE

The high voltage in this Sears
528.41681941 can be varied between 22
and 27 kilovolts when the set is first
turned on. After it has been on for a while,
however, the high voltage creeps up until
it can be varied only between 28 and 30
kilovolts. The B + voltages are all close to
what they should be and stable, but the
boost voltage rises from +800 volts at
turn-on to +870 volts. Any ideas on
this?—J.O., Winthrop, ME

I ran into this some time ago in an RCA
that used a 31JS6 output tube. Here’s
what to do: Check the grid waveform on
your 40KD6 tube with an oscilloscope. If
it is normal at turn on, but the peaks
flatten as the tube warms up, you’ve got
it. The problem is grid emission in the
40KD6. If the peaks flatten enough, it
will make a normal waveform look
almost like a squarewave. The flattened
peaks keep the tube turned on too long,
raising the boost, high voltage, etc. The
only cure is to replace the tube, and check
to make sure the replacement is good; I’ve
gone through 4 or 5 new tubes at times
before I’ve found a good one.

MORE HINTS

Here are a couple more hints from
Mike Danish of Aberdeen Proving
Ground, MD:

The first involves bad colors and low
brightness in an RCA CTC59XD. Resis-
tor RT201 was burnt up. Replacing it,
however, did not help. Looking farther, I
found that I had no control over the CRT
screens. The only thing common to all of
the screens was that they got 600 volts
from the flyback through a IK resistor
and the boost rectifier. When I looked at
the IK resistor, I found that it, too, had
burned up. I tried replacing the resistor,
but the replacement also burned out in
short order. The problem turned out to be
in the boost rectifier. Once it was re-
placed, and a new IK resistor was in-
stalled, everything returned to normal.

The second one involves a Packard-

Bell 1C620WL; that set is actually a GE
C2 chassis. The set had no raster but the
audio was fine. The trouble was traced to
R189 and R191 in the video-output cir-
cuit. Those two resistors had burned up.
When they were replaced, the set ran fine.

HORIZONTAL FOLDOVER

This Zenith HT2382P came in with
intermittent horizontal-foldover in the
center of the screen; the left side of the
screen was perfect but the raster pulled
away from the right side and folded in the
center with a vertical white line about Vi
inch wide. Replacing the horizontal mod-
ule had no effect. When I checked the
driver transformer I found that the resist-
ance was off — it was 40-45 ohms instead
of 96 ohms. A new transformer fixed the
problem, for about three weeks. When I
got it back in the shop I finally found the
true culprit; C227, a 50^F electrolytic
was intermittently opening. Replacing
that capacitor fixed things
permanently. — Danny Joe Davis,
Moundsville, AL

BAD TRACKING

I asked you about an old RCA AM-FM
portable that wouldn’t track at the low end
of the dial. You suggested spraying con-
tact cleaner on the tuning capacitor, and
running the dial back and forth several
times. I did that, and it worked. It also
cleared up a bad drift problem on FM at
the same time. Thanks — Bill Suhy, Strat-
ford, CT

Old-radio restorers take note! The
cause of that problem is a very poor or
corroded contact between the rotor of the
capacitor and the frame. As the rotor
turns, the resistance varies, which of
course changes the capacitance. That
used to be quite common in the old sets,
but I haven’t seen it lately, till now.

OSCILLOSCOPE HINT

We had some Dumont 208 oscillo-
scopes in our lab with problems in the
vertical positioning of the trace . Y our col-
umn in Radio-Electronics about bad
contacts rang a bell. We simply pulled the
6V6 vertical amplifier tubes and then put
them back in. That fixed everything up.
Dumont used the DC plate current of
those tubes to provide the positioning
voltage for the trace, and the humid
summers here had caused some corrosion
in the wafer sockets. — J.R., Ocala, FL

ION BURN

I saw a question in Radio-Electronics
some time ago about what seemed to be
ion bum in a modern CRT. I ran into a
similar problem a while back with a
Zenith 14B36Z. After checking several
things, I read the high voltage and, lo and
behold, it was only 5 kilovolts. The cause
of the problem was a bad flyback. Replac-
ing it cleared everything up. — Bert Balt,
Rochester, NY R-E

JULY 1983

RADIO-ELECTRONICS

Eteofivnics

CALL NOW
AND

RESERVE
YOUR SPACE

• 6* rate $550 per each insertion.

• Reaches 220.500 reaaers.

• Fast reader service cycle.

• Short lead time for the placement of
ads.

• We typeset and layout the ad at no
additional charge.

Call 212-777-6400 to reserve space
Ask for Arline Fishman. Limited num-
ber of pages available. Mail materials
to: mim-ADS. RADIO-ELECTRONICS.
200 Park Ave. South. New York. NY
10003

TELEVISION MODULE includes VHF, UHF,
and CABLE-TV TUNERS, IF AMPLIFIER,
VIDEO DETECTOR, SOUND DETECTOR
and AMPLIFIER, and SYNC PROCESSOR:
$85.00. TELEVISION SIGNAL PROCESS-
ING MANUAL explores standard and non-
standard television: $1 5.95. Add 5% handling
and shipping. Catalog $2.00. Visa and MC
accepted. ORDER DESK (415) 439-7470.
ABEX, P.O. BOX 26601-RZ, SAN FRAN-
CISCO, CA 94126.

CIRCLE 62 ON FREE INFORMATION CARD

CONVERTERS

DESCRAMBLERS-MICROWAVE-Not C

and D grade. Only grade A new, genuine
Oak, Jerrold, Zenith, Hamlin, Pico, Bogner,
Pioneer! Name it! Sine-wave, gated-sync,
vari-sync, in-band, out-band. We sell ’em all!
No order too big or small. Dealers-we can
beat any price. Send $3.00 for catalog to: TV
PRODUCTS CO., 635 Park Avenue, Suite
222, Idaho Falls, ID 83402.

CIRCLE 61 ON FREE INFORMATION CARD

FREE CATALOG OF HARD-TO-FIND
TOOLS is packed with more than 2000 quali-
ty items. Your single source for precision
tools used by electronic technicians, engine-
ers, instrument mechanics, schools, labora-
tories and government agencies. Also con-
tains Jensen’s line of more than 40 tool kits.
Send for your free copy today! JENSEN
TOOLS INC., 7815 46th St., Phoenix, AZ
85040. (602) 968-6231.

CIRCLE 97 ON FREE INFORMATION CARD

display of tip temperature, adjustable tem-
perature 200°F to 900°F. UL listed, low cur-
rent leakage, high insulation. Complete as
shown. 7 tips available, also takes standard
tips. ORDER MODEL 81-XY 168. $79.95
plus shipping. To order call toll free: (800)
423-5336. In California (800) 382-3663. Or
send $79.95 (California residents add sales
tax) plus $5.00, shipping to ORA ELEC-
TRONICS DEPT. RE, 18215 Parthenia St.,
Northridge, CA 91325 (213) 701-5848.

CIRCLE 92 ON FREE INFORMATION CARD

QUALITY TOOLS AT HALF PRICE! Sunnex
manufactures a wide range of high precision,
box joint cutters and pliers for the electronics
industry. Sunnex only sells direct and can
offer you quality tools at the most competitive
prices. A HALF PRICE INTRODUCTORY
OFFER will be enclosed with the catalog
SUNNEX INC., 87 Crescent Rd., Needham,
MA 02194. Phone 1-800-225-8480 (in MA
617-444-4730).

CIRCLE 98 ON FREE INFORMATION CARD

MAGNIFIER LAMP FOR LESS All metal
construction, UL approved 5", 3 x magnifier,
22 watt fluorescent circline lamp. 45" arm
reach, heavy duty clamp mount. Only $59.95
plus shipping. (California residents add sales
tax.) To order call (800) 423-5336. In Califor-
nia, (800) 382-3663 or send $59.95 plus
$5.00 shipping to ORA ELECTRONICS,
1 821 5 Parthenia St., Northridge, CA 91 325
(213) 701-5848.

CIRCLE 96 ON FREE INFORMATION CARD

100

Electronics OTtMO^Md)

SHEET METAL WORKER - The 24" TRIOK
is a Press Brake, Shear and Slip-roll
machine-perfect for research and develop-
ment or maintenance shops. Over a
thousand machine? world wide in little to the
largest companies. For free literature on this
and our other sheet metal working machines
contact: PACIFIC ONE CORPORATION,
513 Superior Ave. Suite K201, Newport
Beach, CA 92663, (714) 645-5962.

CALL NOW
AND

RESERVE
YOUR SPACE

• 6* rate $550 per each insertion.

• Reaches 220.500 readers.

• Fast reader service cycle.

• Short lead time for the placement of
ads.

• We typeset and layout the ad at no
additional charge.

Call 212-777-6400 to reserve space
Ask for Arline Fishman. Limited num-
ber of pages available. Mail materials
to: mini-ADS. RADIO-ELECTRONICS.
200 Park Ave. South. New York. NY
10003.

ELECTRO IMPORTING CO. CATALOG.

This reprint of the historic 176-page catalog
No. 20 gives you an accurate look at the state
of electronics in 1918. Contains everything
from a Zinc Spark Gap to a 1 000-Mile Receiv-
ing Outfit. You can get your own copy of this
modern antique, profusely illustrated, for only
$4.95 plus $1 .00 P&H. Order yours from R-E
BOOKSTORE, Radio-Electronics, 200
Park Avenue South, New York, NY 10003.

3S-WICK STARTS AT 450°F 3S-Wick is

the best and most economical wick. Give it a
try. The special 80c a spool price for a mini-
mum order of 30 spools can be lowered to as
little as 59c a spool when purchased in
1 000 + piece lots. Call our toll free number
1 -800-628-8862 for free sample, and to place
an order (Distributor inquiries welcomed.)

CIRCLE 100 ON FREE INFORMATION CARD

MODERN ELECTRICS. Miniature souvenir
of the first publication ever produced by Gerns-
back Publications. This issue appeared in
April 1908 — just 75 years ago. You can own
your own reprint of this unique first edition for
just $2.50 plus 75C P&H. It’s available from
R-E BOOKSTORE, Radio-Electronics, 200
Park Avenue South, New York, NY 10003

CLOSE OUT - BLOW OUT - LIQUIDATION
SALE - AMATEUR MICROWAVE RECEIV-
ER - REGULARLY $99.50. NOW LIQUIDAT-
ING AT ONLY $59.95 EACH! (Dealer “eight-
pack” for just $399.00) Complete system in-
cludes dish, probe/downconverter, co-ax
cables, power supply, hardware and in-
structions. Top quality units with genuine
#2137 transistors for hi-gain, lo-noise.
ORDER TODAY! Supply limited. Money
order, VISA or Mastercard only. (No C.O.D.
at this price.) T.V. PRODUCTS CO., 635
Park Ave., Dept. 222, Idaho Falls, Idaho
83402. DESCRAMBLERS?? We stock all
types. Send $3.00 for catalog!

OPTIMIZED Graphic Equalizer— NEW Our

latest EQ has been optimized for room
equalization, emphasizing the critical mid-
range. Construction article: Computers &
Electronics 12/82. Near 20-band capability,
but.. .Kit only $100 ppd; M/C, Visa add shpg.
Kit instructions $3.50 (refundable). SYM-
METRIC SOUND SYSTEMS, 856K Lynn
Rose Ct., Santa Rosa, CA 95404, (707) 546-
3895.

CIRCLE 72 ON FREE INFORMATION CARD

APPLIANCE REPAIR HANDBOOKS— 13

volumes by service experts; easy-to-
understand diagrams, illustrations. For major
appliances (air conditioners, refrigerators,
washers, dryers, microwaves, etc.), elec,
housewares, personal-care appliances.
Basics of solid state, setting up shop, test
instruments. $2.65 to $5.90 each. Free
brochure. APPLIANCE SERVICE, PO Box
789, Lombard, IL 60148. 1-(312) 932-9550.
CIRCLE 64 ON FREE INFORMATION CARD

101

JULY 1983

RADIO-ELECTRONICS

TAKE ANY 3 BOOKS

FOR ONLY $ 1 00 EACH
when you join McGraw-Hill'S

Electronics and Control Engineers'
Book Club

(values up to * 87 . 00 )

*If you join now for a trial
period and agree to pur-
chase three more books — at
handsome discounts — over
the next year.

(Publishers’ prices shown)

McGraw-Htu **'■** ~

club that saves you Bl

on the important new
of all publishers.

M Optica Bberra

Go with McGraw-Hill s
EXPERIENCE!

INTUITIVE 1C ELECTRONICS: A
Sophisticated Primer for En-
gineers and Technicians. By

T. M. Frederiksen. 208 pp., Ulus.
Covering both the simplest and the
most complicated 1C designs, this
lively, easy-to-read volume provides
a sophisticated, nonmathematical
explanation of the basic internal
mechanisms common to all semi-
conductor devices.

219/230 $19.95

RADIO HANDBOOK, 22/e. By W Orr

1, 136 pp., more than 1,300 Ulus. Here's
the latest edition of what is universally
regarded as the most useful refer-
ence in the industry. It’s a "course” in
communications, a fact-packed ref-
erence, and a how-to guide — all in a
single book!

582442-6B $39.95

(Counts as 2 of your 3 books)

VLSI TECHNOLOGY By S. M Sze.
672 pp., 400 Ulus., 50 tables. An an-
thology from more than 3,000 tech-
nical papers, by 14 leading experts,
covering everything from crystal
growth to special packaging consid-
erations.

626/863B $32.50

(Counts as 2 of your 3 books)

ANTENNA THEORY: Analysis and
Design. By C. A. Balanis. 816 pp.,
Ulus. Packed with equations, design
procedures, and plenty of nuts-and-
bolts know-how, this is the first place
to turn for answers to all your antenna
design questions.

582493-0B $39.50

(Counts as 2 of your 3 books)

MICROPROCESSOR DATA BOOK.

By S. A. Money. 350 pp., 220 Ulus.
Easily the most comprehensive col-
lection of data on microprocessors and
their support chips available any-
where! Provides important facts on a
wide range of popular devices from
American, European, and Japanese
manufacturers.

427/062B $35.00

(Counts as 2 of your 3 books)

HANDBOOK OF SEMICONDUCTOR
AND BUBBLE MEMORIES. By W A

Triebel and A. D. Chu. 416 pp., il-
lus., over 50 worked-out problems.
This detailed, comprehensive
guide brings you right up to the
minute on such newly developed
devices as the PLA, FIFO, CAM,
CCD, and magnetic bubble
memory — as well as all the stan-
dard storage devices from ROMs
and RAMs to shift registers.
582376-4 $24.95

ELECTRONICS ENGINEERS’

HANDBOOK, 2/e. Edited by D. G.
Fink & D. Christiansen. 2,272 pp.,
2,189 Ulus. This updated and en-
larged edition covers the latest knowl-
edge in the field, including new ad-
vances in integrated circuits, pulsed
and logic circuits, laser technology,
telecommunications, and much more.
209/81 2 A $75.00

(Counts as 3 of your 3 books)

ELECTRONIC COMMUNICATION,

4/e. By-R. L. Shrader. 801 pp., 870
Ulus. This thoroughly updated edi-
tion offers all the theory and fun-
damentals you need to prepare
yourself for the FCC commercial
and amateur grade license exami-
nations — and pass them the first
time!

MICROPROCESSOR APPLICATIONS
HANDBOOK. Editor-in Chief, D. F.
Stout. 472 pp., 284 Ulus. At last — a
reference guide to microprocessor
applications to help you make your
systems timely, versatile, and
cost-effective.

617/988B $35.00

(Counts as 2 of your 3 books)

SIGNALS AND SYSTEMS. By A Op-

penheim, A. Willsky, and I. Young. 869
pp., more than 350 Ulus. This unique
volume presents a comprehensive
discussion of methods for analyzing
discrete-time systems. Includes a look
at feedback, convolution, and other
concepts not treated in depth else-
where.

582674-7B $32.50

(Counts as 2 of your 3 books)

OPTICAL FIBER COMMUNICA-
TIONS. By G. Keiser. 416 pp., Ulus.
For those with little or no prior expe-
rience with optical fibers, the perfect
book to walk you through a typical
system.

334/676B $35.95

(Counts as 2 of your 3 books )

PCM AND DIGITAL TRANSMIS-
SION SYSTEMS. By R. Owen. 320
pp., 186 Ulus. This useful volume al-
lows newcomers to the field to famil-
iarize themselves with its problems
and equipment in two weeks, instead
of the three months it would ordinarily
take.

479/542B $30.00

(Counts as 2 of your 3 books)

571/503

$26.95

MANUAL OF ACTIVE FILTER DE-

INTRODUCTION TO RADAR SYS-
TEMS, 2/e. By M. I. Skolnik. 698
pp., 244 Ulus. This new edition of a
widely used text on radar from the
systems engineer’s point of view
brings you full discussions of the
many major changes that have oc-
curred in the field recently.

579/091 B $39.95

(Counts as 2 of your 3 books)

DIGITAL HARDWARE DESIGN. By

J. B. Peatman. 428pp., over 400 Ulus.
Taking you beyond the microcomput-
er, this guide reexamines traditional
techniques and focuses on the de-
sign of circuitry too fast for the micro-
computer alone.

491/321 B $35.50

(Counts as 2 of your 3 books)

MODERN ELECTRONIC CIRCUITS
REFERENCE MANUAL. By J Mar-
kus. 1,264 pp., 3,666 circuit dia-
grams. Complete with values of com-
ponents and suggestions for revisions,
plus the original source of each circuit
in case you want additional perfor-
mance or construction details.
404/461 A $67.95

(Counts as 3 of your 3 books)

SIGN, 2/e. By J. L. Hilburn and D. E.
Johnson. 225 pp., 157 easy-to-use
design graphs. This ingenious man-
ual enables you to design filter cir-
cuits for virtually any application in
minutes — without making a single
computation ! Covers all the latest de-
signs.

287/694B $37.50

(Counts as 2 of your 3 books)

102

DIGITAL CIRCUITS AND MICRO-
PROCESSORS. By H. Taub. 608pp.,
heavily Ulus. This fast-paced, care-
fully written guide gives you thor-
ough explanations of all the basic
principles of digital systems and
logic design — plusa solid introduc-
tion to microprocessors and micro-
processor-based designs.

629/455B $32.95

( Counts as 2 of your 3 books)

DIGITAL COMMUNICATIONS. By J.

G. Proakis. 624 pp., Ulus. A wealth of
new material, information about
spread spectrum signals, requiring a
minimum of math to get through it.
509/271 B $37.50

(Counts as 2 of your 3 books)

ELECTRONICS ENGINEERING FOR
PROFESSIONAL ENGINEERS' EX-
AMINATIONS. By C. R. Hafer. 336
pp., more than 200 Ulus. Actually
two books in one — a quick prepara-
tion manual to help you pass your
P.E. exams on the first try and a
rich source of practical electronics
engineering information and
know-how.

254/303 $27.50

MICROPROCESSOR SUPPORT
CHIPS Theory, Design and Ap-
plication. By J. J. Byers. 228 pp.,
170 Ulus. Everything from pinouts to
operating characteristics is spelled out
for telecommunications, power sup-
plies, interfaces, control, video and
A/D and D/A converters.

095/183B $38.00

(Counts as 2 of your 3 books)

INTEGRATED CIRCUIT FABRICA-
TION TECHNOLOGY. By D J. Elliott
480 pp., 220 Ulus. Covering every step
in the transformation of a silicon chip
to an integrated circuit, this is the first
book to combine, in a single volume,
a cohesive examination of the equip-
ment, materials, and techniques of 1C
fabrication.

192/383 $29.75

STANDARD HANDBOOK FOR
ELECTRICAL ENGINEERS, 11/e. By

D. G. Fink and H. Beaty. 2,448 pp.,
1,414 Ulus. Today’s most widely
used source of electrical engineer-
ing information and data serves
you as no other single work when
you need detailed, timely, and reli-
able facts

209/74XA $65.95

(Counts as 3 of your 3 books)

McGraw-HIII'S NATIONAL ELEC-
TRICAL CODE® HANDBOOK, 17/e.

By J.F. McPartland. 1,162 pp.,
1,096 Ulus. Bigger and better than
ever! This mammoth reference ex-
plains and clarifies the many com-
plex provisions of the current
(1981) Code® to help you meet rules
exactly and pass inspections the
very first time.

456/933 $26.50

HANDBOOK OF ELECTRONIC
PACKAGING DESIGN AND ENGI-
NEERING. By B. Matisoff. 480 pp.,
312 Ulus. This handy volume exam-
ines the broad array of packaging
techniques available today, providing
the data you need to select the best
one for a given application. Stresses
the interplay between design criteria.
582515-5B $32.50

(Counts as 2 of your 3 books)

ANALYSIS AND DESIGN OF DIGI-
TAL INTEGRATED CIRCUITS. By D

A. Hodges & H. G. Jackson. 448 pp.,
Ulus. The only book available written
from a quantitative point of view for
those who design as well as use ICs.

291/535 $27.50

Be sure to
consider these
important
titles as well!

RADAR TRANSMITTERS. By G W.

Ewell.

198/438 $26.95

16-BIT MICROPROCESSOR SYS-
TEMS. By Texas Instruments, Inc.
637/601 B $45.00

(Counts as 2 of your 3 books)

ELECTRONIC CIRCUITS NOTEBOOK:
Proven Designs for Systems Ap-
plications. Edited by S. Weber.

192/448B $35.50

(Counts as 2 of your 3 books)

optical FIBER SYSTEMS: Tech-
nology, Design, and Applica-
tions. By C. K. Kao.

332/770 $26.00

INTRODUCTION TO THE THEORY
AND DESIGN OF ACTIVE FILTERS. By

L. P. Huelsman & P. E. Allen.

308/543B $34.50

(Counts as 2 of your 3 books)

MICROELECTRONICS. By J.

Millman.

423/27XB $35.95

(Counts as 2 of your 3 books)

HANDBOOK OF OPERATIONAL
AMPLIFIER CIRCUIT DESIGN. By D.

E. Stout & M. Kaufman.

617/97XB $38.00

(Counts as 2 of your 3 books)

MICROCOMPUTER-BASED DESIGN.

By J. Peatman.

491/380B $35.95

(Counts as 2 of your 3 books)

BIT-SLICE MICROPROCESSOR DE-
SIGN. By J. Mick & J. Brick.

417/814 $29.50

NETWORK SYSTEMS. By R Sharma
& P. DeSousa.

582557-0 $29.95

ENGINEERING MATHEMATICS
HANDBOOK, 2/e. By J. J. Tuma.
654/298B $31.25

(Counts as 2 of your 3 books)

Why YOU should join now!

■ BEST AND NEWEST BOOKS IN YOUR FIELD! Books are selected from a wide
range of publishers by expert editors and consultants to give vou continuing access
to the best and latest books in your field.

McGraw-Hill Book Clubs
Electronics and Control Engineers'

Book Club

P.O. Box 582, Hightstown, New Jersey 08520

Please enroll me as a member and send me the three

■ BIG SAVINGS! Build your library and save money too! Savings ranging up to 30%
or more off publishers’ list prices — usually 20% to 25%.

BONUS BOOKS! You will immediately begin to participate in our Bonus
Book Plan that allows you savings up to 80% off the publisher’s prices
of many professional and general interest books!

choices I have listed below. Bill me only S3 .00 plus local
tax, postage, and handling. If not satisfied, I may return
the books within 10 days and my membership will be
canceled. I agree to purchase a minimum of three addi-
tional books during mv first year of membership as out-
lined under the Club plan described in this ad. A shipping
and handling charge is added to all shipments.

Indicate below by number the books you want. A few ex-
pensive books (noted in the descriptions) count as more
than one choice.

■ CONVENIENCE! 12-14 times a year [about once every 3-4 weeks] you receive the
Club Bulletin FREE. It fully describes the Main Selection and alternate selections.
A dated Reply Card is included. If you want the Main Selection, you simply do
nothing — it will be shipped automatically. If you want an alternate selection — or
no book at all — you simply indicate it on the Reply Card and return it bv the date
specified. You will have at least 10 days to decide. If, because of late delivery of the
Bulletin you receive a Main Selection you do not want you may return it for credit
at the Club’s expense.

As a Club Member you agree only to the purchase of three additional books during
your first year of membership. Membership may be discontinued by either vou or
the Club at any time after you have purchased the three additional books.

Other McGraw-Hill Book Clubs:

Accountants’ and Controllers’ Book Club • Architects’ Book Club • Byte Bpok Club • Chemical
Engineers’ Book Club • Civil Engineers’ Book Club • Mechanical Engineers’ Book Club

Name

Address/Apt.

City/State/Zip

This order subject to acceptance bv McGraw-Hill. All prices
subject to change without notice. Offer good only to new
members. Orders from outside the U.S. cannot be ac-
cepted.

For more information, write to:

McGraw-Hill Book Clubs • P.O. Box 582, Hightstown, NJ 08520

E33606

105

JULY 1983

RADIO-ELECTRONICS

MARKET CENTER

SATELLITE TELEVISION

SATELLITE antennas build 10' wood under $160
metal $93 plans $40. PROTOTYPE ENGINEERS,

Box 1812 Deming, NM 88030.

SATELLITE TV receiver breakthrough! Build
your own commercial quality receiver now! In-
struction manuals, schematics, circuit boards!
Send stamped envelope: XANDI, Box 25647, De-
pt. 21 L, Tempe, AZ 85282.

SATELLITE Television. Free wholesale price list!
Save big! COMMUNICATIONS CONSULTANTS,

PO Box 5099, Fort Smith, AR 72913.

INTERESTED in home satellite television? Don’t
buy anything until you’ve read Homesat Handbook
& Buyers Guide. Our book tells everything about
home satellite TV and may save you hundreds,
even thousands of dollars in your selection and
installation of a system! $10.00: H & G HOMESAT
SERVICES, Box 422, Seaford, N.Y. 11783.

BUSINESS OPPORTUNITIES

PROJECTION TV... Make $$$ assembling pro-
jectors... Easy... Results comparable to $2500.00
projectors... Your total cost less than $17.00. ...
Plans, lens & dealers information $15.50. ... Illus-
trated information free ... MACROCOMGKX,
Washington Crossing, PA 1 8977. Credit card orders
24 hours. (215) 736-2880.

PROFITABLE ONE-MAN

ELECTRONIC FACTORY

Investment unnecessary, knowledge not re-
quired, sales handled by professionals. Ideal
home business. Write today for- facts'

Postcard will do, Barta-RE-X, Box 248,
Walnut Creek, CA 94597.

MECHANICALLY inclined individuals desiring
ownership of small electronics manufacturing busi-
ness — without investment. Write: BUSINESSES,
92-R, Brighton llth, Brooklyn, NY 11235.

WHOLESALE MATV/CATV/VCR equipment, an-
tennas, audio cables, adapters, original/
replacement cartridges & styli, telephone accessor-
ies, radios, cassette recorders, speakers, etc. Send
letterhead for free catalog (212) 897-0509. D&WR,
69-19 Booth, Flushing, NY 11374.

COMPUTERS

$44,000 first year in computers. Get in now! Free
details. DIGATEK CORPORATION, Suite T2, 2723
West Butler Drive, Phoenix, AZ 85021.

FREE high technology semiconductors catalog
32bit microprocessor, 64KDRAM, speech syn-
thesizer kits, 128KEPROM, no minimum or piece
order, toll free number, etc., etc., H.T.S., Box 213
Tustin, CA 9268L (714) 731-8859.

SATELLITE TV WEEK

The most complete weekly listings.

Send $1 for simple copy.

P.O. Box 308, Fortune, California 95540

C«ll (too) 3JI-W7 • California (707) 7*5-1476

WIND power an investment in the future. The
right decision is essential. Information $2.00
WINDESIGN, Box 138, Boston, NY 14025.

HOME burglar alarms. Career opportunities. High
income. Information $2.00. SECURITY ELEC-
TRONICS INTERNATIONAL,, PO Box 1456-XE,
Grand Rapids. Ml 49501.

AT LAST!!

CABLE devices for ‘beeping’ or ‘buzzing’ channels.
Details $4.00. Money back guarantee. CATV IN-
FORMATION CENTER, PO Box 17621, Ft. Laud.,
FL 33318.

CB EQUIPMENT

CB radio books, kits, modifications, free catalog.
APS, POB 263RE, Newport, Rl 02840.

VIC-20

CAPACITOR tester/meter. Connects to userport.
Displays values 10-PFD through 650-MFD. In-
dicates shorts and opens. Needs no extra memory.
Guaranteed. Wired tester and cassette program.
$39.95. SANDI ELECTRONICS, 203 Cambridge
Belton, MO 64012.

To run your own classified ad, put one word on each of the lines below and send this form along with your check
for $1.90 per word (minimum 15 words) to:

Radio-Electronics, 200 Park Avenue South, N.Y., N.Y. 10003

ORDER FORM

PLEASE INDICATE in which category of classified advertising you wish your ad to
appear. For special headings, there is a surcharge of $15.00.

( ) Plans/Kits ( ) Business Opportunities ( ) For Sale
( ) Education/Instruction ( ) Wanted ( ) Satellite Television

Special Category: $15.00

PLEASE PRINT EACH WORD SEPARATELY, IN BLOCK LETTERS.)

WIRELESS MICROPHONES

BIG savings on Cony transmitters— up to 30%
off! Send two stamps for catalog. S.E. CORP, Box
1132-RC, Yorba Linda, CA 92686.

SECURITY-MONITORING
DEVICES

ULTRA-miniature, super-range wireless FM
transmitters as small as 7/8" long! Micro wireless
telephone transmitter, voice activators, telephone
voice changers, six-channel crystal communication
systems, and more! Professional, high-tech mic-
roelectronics now available to you. Free brochures.
EXTENDO-TAPE SYSTEMS, Dept. R-E, Box LC,
Temple Terrace, FL 33687 (813) 985-3014.

XENON FLASH LAMPS

CALL OR WRITE FOR INFORMATION.

TEC/WEST (USA) INC.

10889 WILSHIRE BLVD., SUITE 740
LOS ANGELES, CA 90024-4299
CA: 213/208-5529 • OUTSIDE CA: 1-800-421-7215

PLEASE INCLUDE FOR OUR FILES YOUR PERMANENT ADDRESS AND PHONE NUMBER.

CLASSIFIED COMMERCIAL RATE for firms or individuals offering comercial products or sen/ices).

$1 .90 per word prepaid (no charge for zip code)...MINIMUM 15 WORDS. 5% discount for 6 issues,
10% for 12 issues within one year, if prepaid.

NON-COMMERCIAL RATE (for individuals who want to buy or sell a personal item) $1.25 per word
prepaid. ..no minimum.

ONLY FIRST WORD AND NAME set in bold caps. Additional bold face (not available as all caps) at 1 5c
per word. All copy subject to publisher’s approval. ADVERTISEMENTS USING P.O. BOX ADDRESS
WILL NOT BE ACCEPTED UNTIL ADVERTISER SUPPLIES PUBLISHER WITH PERMANENT
ADDRESS AND PHONE NUMBER. Copy to be in our hands on the 20th of the third month preceding the
date of the issue (i.e., August issue closes May 20th). When normal closing date falls on Saturday
Sunday, or a holiday, issue closes on preceding working day.

106

EDUCATION & INSTRUCTION

EARN your university degree through evaluation
assessment, of existing education, experience,
achievements. Call, (614) 863-1791, or write,
ASSESSMENT, Box 13130 R, Columbus, OH
43213.

YOUR own radio station! AM, FM, cable, licensed,
unlicensed. Low cost transmitter kits, free info.
BROADCASTING, Box 130-F7, CA 95969.

ELECTRONICS computer books. International
publishers. Lowest rates. Ask list. BUSINESS PRO-
MOTION, Lajpat Rai Market, Delhi, India.

REEL TO REEL TAPES

TRUCKLOAD sale Ampex high quality open reel
tape, 1 800- or 2400-feet on 7- inch reels, used once.
Case of 40, $45.00. Cassettes available. VALTECH
ELECTRONICS, Box 6-RE, Richboro, PA 18954.

CABLE TV

CHANNEL 3— 60dB notch filter. 63.5MHz. $32.
CROSLEY, Dept 606, Box 840, Champlain, NY
12919.

CB RADIO

GET more CB channels and range! Frequency
expanders, boosters, speech processors, FM con-
verters, PLL/slider tricks, how-to books, plans, mod-
ifications. Catalog $2.00. CB CITY, Box 31500 RE,
Phoenix, AZ 85046.

CONVERTERS

GATED pulse wave UHF (speaker box type), has
true AGC, parts $125.00. The following have sound
out of the TV like normal with only an antenna con-
nection to the TV or VCR. Deluxe MB sine wave
UHF, has true AGC, parts $150.00. Digital sync
suppression/active video inversion VHF/UHF FV-
4,, has true AGC, parts $225. Mitsumi tuner module
with AGC, AFT, 504KHZ, etc., $60.00. Quantity dis-
counts. Plans: large SASE (54 cents postage). Free
shipping/handling. 1-312/267-3455. LSR
ENGINEERING, Dept. RE, PO Box 6075, Chicago,
IL 60680.

LONG-PLAY RECORDER

FOUR unique models, allowing up to 20 recording
hours on a single ordinary cassette! Models as small
as 1V2 pounds! Fidelity, features, and quality un-
available elsewhere. Free brochures. EXTENDO-
TAPE SYSTEMS, Dept. R-E, Box LC, Temple Ter-
race, FL 33687 (813) 985-3014.

SAVE CABLE TV $$

CABLE TV Consumer Buyers Guide. Guaranteed
lowest prices on cable TV devices and converters.
We are an independent consumer service. Manual
includes info on which equipment works on your
cable system. $8.00. CATV INFORMATION CEN-
TER, PO Box 17621, Ft. Laud., FL 33318.

TI-99/4A SOFTWARE

TI-99/4A owners. Games and application software
on cassettes as low as $5.95. Write: TI-99/4A CAS-
SETTE SOFTWARE, 4129 Abercorn Rd„ Knoxvil-
le, TN 37921.

TIMEX/SINCLAIR SOFTWARE

T/S 1000 programs financeaid (barcharts, interest,
record keeping), math quiz (20 levels), electrosolve
(solves most electronics circuit problems), $6.95
each. BILL KEMP, Box 26086, Bluff Park, AL
35226.

UPGRADE TELEPHONES

ADD THESE EASY-TO-INSTALL SPECIAL. FEATURES
Hold Busy Silencer Circuit

Allows you to put calls on hold. Also lets you silence bell or put phone on
busy '. Plans: S4 00: Kit: S4.00 - S2. 00 phone.

Intercom Circuit

Lets you use phones as an intercom. No extra wiring required. Less costly
than wireless models. Plans: S7.Q0: Kit: SI 5.00 + S5.00 phone.

Kms nclude plans parts and hoard. When ordering-kits, add S2.00 for postage.
'Send SASE for more information.

dB Enterprises Box 8 Oradell. NJ 07649

TRS-80 COLOR COMPUTER

COLOR COMPUTER OWNERS— 1 2 different pro-
grams on cassette for only $1 5.00! Games, quizzes,
etc. Send check or money order to: QJN ENTER-
PRISES, PO Box 983, Sarasota, FL 33578. Fla.
residents add 5% sales tax.

REVERBERATION
FOR ORGANS

Solid state with controls for rever-
beration and room size.

EVERY ORGAN SHOULD
OWN ONE. Send for free flyer—

DEVTRONIX ORGANS, INC.

6101 WAREHOUSE WAY
SACRAMENTO, CALIFORNIA 95826 Dept. B

PLANS & KITS

SUBSCRIPTION TV manual, covers both sine
wave and gated sync system, only $1 2.95. Includes
theory, circuits, waveforms, and trouble-shooting
hints. Video game cartridges are easy and in-
expensive to duplicate. Plans $9.95. Information
$2.00, refundable. RANDOM ACCESS (Formerly D
& S Enterprises), Box 41 770R, Phoenix, AZ 85080.

CATALOG! 40 pages of neat electronics parts and
kits. Send 50 cents, refundable first order. BEC
ELECTRONICS, Box 401244R, Garland, TX
75046.

UHF over the air all types, cable systems. Coming
soon 2 new complicated UHF units (compatible with
satellite owners). Now brand new Deluxe III gated
pulse unit, sound through TV. Call for information
301-882-9362, or send $2.00 (refundable) for cata-
log. SATELLITE ELECTRONICS, PO Box 9534,
Baltimore, MD 21237.

FUNCTION GENERATOR KIT $59.95
Auto-Ranging Cap-meter kit $79.95

Phone 209-772-2076

Write or Phone for FREE CATALOG

INCREDIBLE price and quality for amplifier, power
supply, and many many new electronics kits. Write
now for your absolutely free catalog. IN-
TERNATIONAL POLYTECHNIQUES, PO Box
862R, New York, NY 10002.

BREADBOARD using spirafit lead kit. Pretinned,
spiral leads stretch to desired lengths. No cutting,
stripping, wrapping required. Send 50 cents for
sample, details, prices free. CALDER TRADING,
720 Smithtown Ave., Bohemia, NY 11716.

FUN kits — low cost. Easy to build educational
electronics projects. Handbook/catalog $1.00.

TRIANGLE ELECTRONICS, 89 Arkay Drive,
Hauppauge, NY 1 1788.

MINI FM MIC

Compact size, only 2" x 1 ” x 3 /4". T ransmit
to FM radio 88-108 MHz. Exceptional au-
dio quality. Transmits stable signal up to
900 ft. Complete kit incl. case, battery &
instructions. Only $15.95. Assembled
$20.95. Add $1.55 S&H ea. CA. RES.
ADD TAX. Send 20c stamp for brochure.
S.E. Corp., Box 1132-RE
Yorba Linda, CA. 92686

TIMEX/SINCLAIR 1000/ZX81 How-To hardware
upgrade book. Covering: buffered expansion in-
terface, serial interface, standard printer interface,
and more. $6.95 ppd 10-day money back guaran-
teed. INNER KNOWLEDGE COMPUTERS & PER-
IPHERALS, 5944 N.E. Sandy Blvd., Portland, OR
97213.

SUBSCRIPTION TV KITS

UHF Gated Pulse Kit.....$39.00

UHF Sinewave Kit. $37.00

Special Both Kits. $59.00

Informative Catalog.. — $ 2.00

Kits include all parts, manual and an
etched & drilled PC board. Send for
our * Informative Catalog " and find
out what type you need.

J & W ELECTRONICS, INC.

P. O. BOX 61-B
CUMBERLAND, Rl. 02864

OWN a tone remote retrieve telephone answering
device? Throw your tone device away. Retrieve
messages with any standard Touch-Tone ~ s tele-
phone. Plans $10.95 — kit including PC board
$39.95 — check or M.O.— APP-COM, PO Box
1031, New Castle, IN 47362.

CATALOG— transmitters, linears, MDS
downconverters, scramblers, broadcasting, CB,
hobby plans & kits. $1.00. PANAXIS, Box 130-F7,
Paradise, CA 95969.

NEW FM transmitter kit. Great for experimenters.
Instructions and parts only $1 9.95. Buy now. TUCK-
ER ENTERPRISES, PO Box 1 01 20, Alexandria, V A
22310-0120.

CONTROL and read up to 256 devices. Plugs into
Radio Shack model III. Simple construction, soft-
ware included. Plans $15.00. SPECIALTY
ENGINEERING & MFG., Inc. PO Box 120, Gon-
zales, TX 78629.

ELECTRONIC combination lock, patented. Plans
available for $3.00 and SASE from JINN, Box 764,
Herndon, VA 22070.

TIMEX/Sinclair kits: 2parallel and 2RS232CI/0
ports $69.95. Color graphics and sound w/16K
RAM $179.95. 32K RAM $88.95. All kits furnished
with high quality PC boards, and plug into the ST-50,
fully buffered, 8slot motherboard $149.95. CW/TTY
interface available soon. Brochure $1.00 (refund-
able). SIGMA-TECHNOLOGY, Dept. K, Box 971,
Va. Beach, VA 23451 .

CUSTOM PC boards and photo masks from
sketches, schematics, or artwork. Free brochure on
services, products, and kits: TTL logic probe,
$13.35. AIE, Box 2287, Arcadia, FL 33821.

PRINTED circuit boards. Quick prototypes, pro-
duction, design, reflow solder. Send print or descrip-
tion for quote to KIT CIRCUITS, Box 235 Clawson,
Ml 48017.

LIGHT display sequencer kits. Send stamp for
flyer. DESIGN SPECIALTY, P.O. Box 1995, Hunt-
ington Beach, CA 92647.

PROJECTION TV ... Convert your TV to project 7
foot picture. Results comparable to $2,500 pro-
jector... Total cost less than $20.00 ... Plans and
lens $17.50... Illustrated information free... Credit
card orders 24 hours. (215) 736-3979. MACROCO-
MAGK, Washington Crossing, PA 18977

ELECTRONIC touch light control pad five modes
dim, medium, bright, delay, and off. Two kits avail-
able. Write for free brochure. EXOTIC ELEC-
TRONIC IDEAS, PO Box 446, Lake Bluff, IL 60044.

SINE wave decoder problems? Manual includes
trouble shooting, alignment, antenna hookup, im-
provements, theory. $1 5.00. SIGNAL, Box 251 2-R,
Culver City, CA 90230.

PROFESSIONAL electronics devices plans,
kits, P.C circuitry, famous drop-in microphone car-
tridge, debugging equipment, more items available-
.For information send $3.00. MOUNTAIN ELEC-
TRONICS, R.2, Box 30, Charlotte, TN 37036.

FREE phone calls made by users. Electronics de-
vice report, plans sold for information, education
only. $7.50: DISTRIBUTORS MART, Dept. RE73,
Box 333, Modena, NY 12548.

SAVE energy! Build a computerized thermostat.
Schematic and software $5.00. GLOVATRON, PO
Box 559, East Detroit, Ml 48021.

MICROWAVE television “downconverters.” Ex-
clusive new five stage design. Easily assembled.
Catalog: $2.00 (refundable). NDS, Box 12652R,
Dallas, 75225.

107

JULY 1983

RADIO-ELECTRONICS

FOR SALE

NEW Repair any TV ... Easy. Anyone can do it.

Write RESEARCH, Box 51 7C, Brea, CA 92621.

CABLE TV products: Wireless, corded, & settop
converters. Send $3.00 for catalog. ADDITIONAL
OUTLET CORP., 231 E. Commercial Blvd., Ft.
Lauderdale, FL 33334.

CABLE TV SECRETS— the outlaw publication the
cable companies tried to ban. HBO, Movie Channel,
Showtime, descramblers, converters, etc. Suppli-
ers list included. Send. $7.95 to CABLE FACTS,
Box 711-R Pataskala, OH 43062.

PCB 1 5 cents sq-in. Free drilling. Quantity discount.

INTERNATIONAL ENTERPRISE, 6452 Hazel Cir-
cle, Simi Valley, CA 93063.

RESISTORS VWV & V 2 W 5%C.F. 3 cents. 1%M.F.
All values. No minimums Volume discounts. Write
JR INDUSTRIES, 5834-B Swancreek, Toledo, OH
43614.

RELIABLE MICROWAVE TV ANTENNAS
2.1 to Z6 GHz
Frequency Range

j 34db System Gain (or Greater)

Complete System (pictured) $119.95
^ i Down Converter Probe Style
mi (Assembled & Tested) $ 49.95
Ip Power Supply (12V to 16V DO)
m (Assembled & Tested) $ 39.95

PETERSON

ELECTRONICS

4558 Auburn Blvd.
Sacramento. CA 95841
(916) 486-9071

SPECIAL QUANTITY PRICING
Dealers Wanted - COD S

1 YEAR WARRANTY
PARTS & LABOR

COLOR computer VIC-20 programs hardware Rtty
code EPROM Progammer RS-232. FRANK LY-
MAN, Box 3091, Nashua, NH 03061.

THE Intelligence Library. Restricted technical
secrets — books on electronic surveillance, lock-
picking, demolitions, investigation, etc. Free
brochures: MENTOR, Dept. Z, 135-53 No. Blvd.,
Flushing, NY 11354.

SURVEILLANCE device schematics, books on
electronic surveillance methods & equipment,
locksmithing, covert technologies, etc. Catalog,
$1.00. MENTOR, Dept. Z, 135-53 N. Blvd., Flushing,
NY 11354.

.125 aluminum — make your own chassis! Cut to
size, squares, rectangles only. 6 cents sq. in.,

$1 0.00 minimum, $2.00 handling. Shipped UPS col-
lect. Send dimension(s) of piece(s) to: O’DAY, PO
Box 248, Lansing, IL 60438.

★★★★★★★★★★★★★★★★★★★★★★★★★

J QUALITY MICROWAVE TV SYSTEMS X

Jf ★★★★★★★★★★★★★★★★★★★★★★★ Jf

J Complete Systems From $ 69 95 J

* *

★★★★★★★★★★★★★★★★★★★★★★★★★

108

1.9 to 2.5
GHz

Antennas

Galaxy

Electronics

6007 N.61stAve.
Glendale, Az.
85301

1-602-247-1151

1-800-247-1151

COD’S / Dealers Wanted

WIRELESS THERMOSTAT

TELESTAT - a portable, wireless thermostat that
moves with you. From room to room. To the TV
room after dinner. To the bedroom at night. To the
kitchen early in the morning. Your furnace works
to keep the room where you and Telestat are, at
a comfortable level. Telestat saves you money
because your furnace works only when needed,
instead of running continuously. Use with forced
air furnaces and air conditioners. That’s double the
savings. Year in and year out. $94.95*

* SPECIAL THROUGH AUG. 31, 1983
CALL 1 -800-426-8075 or write

COMMUNICATIONS RESEARCH CORPORATION

1720 - 130th Ave. N.E. Bellevue, WA 98005

UNUSUAL UHF subscription TV kits. Also micro-
wave downconverters. Catalog 50 cents. TROJAN,
2920 Shelby, Indianapolis, IN 46203.

TELEPHONES— extensive selection— parts,
accessories, systems. Free catalog. NDS, Box
35444, Los Angeles, CA 90035-0444 (213) 935-
9900.

PRINTED circuit boards: quotes free. SASE to

JAHMAAL ELECTRONIC SUPPORT, PO Box

397, Troy, NY 12181.

ELECTRONICS catalog: Scanners, CB, video. All
kinds of electronics goodies. Send $1.00 refundable.
CLEM ELECTRONICS, 1520 N. Pacific, Fresno,
CA 93728.

Full Size Keyboard
Conversion

103/4 X 71/4 X 2 1 /*

For
Your
ZX81/

TS1000

SUN KD-81

$ 89 95 Easy To Install

No Soldering - No Modifications

41 Ksys with Full Size Space Bar • Allows Touch Typing
Same Key Layouts as Sinclair • Two Color Keytops
Keyboard Case Holds Both Keyboard and Computer
Commands and Graphics Spelled Out on Keytops
Rear Cutout for Any RAM or Expansion Modules
16K Piggyback RAM Module . P/N MX- 16 $49.95

^-SUNTRON/CS CO.. >nc.

In Calif Call 213-644-1149
| mSCEEEiE^ Outside Calif Call 1-800-421-5775

Or send Check or M.O. to:

P.0. Box 1957 Hawthorne CA 99250

California residents add 6V4% sales tax.

Add $4.00 ship/h3ndling. VISA/Msstercard include expiration date.

TUBES — all types, discount prices. Many oldies
and hard-to-find types. SASE for list. ANTIQUE
RADIO & TUBE CO., Dept. 701, 1725 W. Univer-
sity, Tempe, AZ 85281.

XFORTH — Forth-79 standard sub-set plus extra
utilities. 10K + available for user code. Or cassette
for 1 6K ZX-81 . $25.00 + $1.00 P&H. Arkansas resi-
dents add $1.00. HAWG WILD SOFTWARE Box
7668-R, Little Rock, AR 72207.

TRANSPOSERS digital rhythm displays super
cymbal, many more inexpensive accessories, all
organs. Send for free brochure. SACHA IN-
TERNATIONAL, 943 Archer Street, San Diego, CA
92109.

'Bare Power Supply Boards"

(FOR ALL T0-220 3 TERMINAL REGULATORS)

"Four Styles In Stock" All Boards 2"x3" - G10

• 7800 Positive Fixed Silk Screened - Soldermasked

• 7900 Negative Fixed Make Projects A Snap!

• 31 7T Positive Adjustable Includes: Detailed Instructions

• 337T Negative Adjustable Parts Lists-Schematics-Design Tips

ea. - 4 for $9.00 add $1.00 postage b handling

MIDWEST TECHNICAL
P O. BOX 272, AURORA. IL 60507

HI-REL mil-spec metal film resistors. RN55’s,
RNC60’s, etc. at super low prices. Contact us for
free inventory listing and price list. IN-
TERMOUNTAIN ELECTRONICS, Box 531 , Boise,
ID 83701 (208) 384-9755.

PRINTED-circuit boards: single side, prototype,
and quantity, quick delivery. Send positive, free
quotes. FABTRON, Box 925, Dept. C, Columbia,
TN 38401 (615) 381-1143.

SUPER summertime surplus savings! Free flyer.
ELECTRONIX LTD., Dept. R-7, 3214 S. Norton,
Sioux Falls, SD 57105.

RADIO West — still the best for SW/MW DX receiv-
ers and receiver modifications! Catalog 50 cents.
RADIO WEST, 3417 Purer Road, Dept RE, Es-
condido, CA 92025 (619) 741-2891.

SPECIAL sale — 40-channel TV converter, built-in
fine tuning. Only $28.95, add $2.50 postage and
handling. Free bargain catalog. IN-X-SALES, Box
222, Medford, MA 02155.

SPEAKER & ELECTRONICS CATALOG
1001 BARGAINS IN SPEAKERS

Tel.: 1 (816) 842 5092

1901 MCGEE STREET KANSAS CITY, MO. 64108

SCANNER accessories and crystals. Free catalog
— best prices anywhere. SCANNER PLUS, Box 45,
Tilton, NH 03276 (603) 286-3082.

SCANNER/monitor accessories — kits and factory
assembled. Free catalog. CAPRI ELECTRONICS,
Route 1 R, Canon, GA 30520.

ZX81/TS1000: 25 Family Fun Programs for 16K!
You type and save! Send $7.50 to H. DAILY, Box
553, Valley Center, CA 92082.

MICROWAVE antenna 38 dB gain, slotted dish,
probe, power supply, 60’ cable, warranty. AMA
SYSTEMS, PO Box 1354, Sandy, UT 84091 . Only
$79.95.

THE BEST PLACE to BUY. SELL or
TRADE NEW and USED EQUIPMENT

NUTS & VOLTS MAGAZINE

BOX. Ill I -E • PLACENTIA. CA 92670
(714) 632-7721

Join Thousands of Reader? Nationwide
Every Month

ONE YEAR U.S. SUBSCRIPTIONS
S7.00 - 3rd CUm • SI 2. SO . 1st Class
S 25.00 • Lifetime - 3rd CUm

TMT (OUtTMCMT
MCKOWAVC
SATtUJTt
A 0040 VISUAL
New PftOOUCTS

AKTKJUt ILJCT.

publications
PLANS • SMVtCCS

Many Happy
Returns

TakefW-

. stock%.s#o-

m^merica.

NEW ITEMS, SUPER VALUES AT THE PARTS PLACE

No Minimum Order! Friendly Service! See Before You Buy!

Telephone Ringer 1C Sale! 25-Range Multitester

NEW! 399

IF, FM & Vi deo ICs

I 79

8-Pin DIP

• Phone Line Powered

♦ ideal for Remote
Ringers

TCM1512A. Detects ring and drives an exter-
nal piezo element (not inci.). 800 to 2 kHz
output with 10 Hz warble, determined by ex-
ternal resistor. On-chip static protection and
anti-tap circuitry. 276-1302 3.99

Enclose Your Project!

NEW!

jn. , 1 's 499

Aluminum. Eggshell white with black top.
Complete with hardware and rubber feet.

Size

Cat. No.

Price

1 15 /iex 41/4 x4Va"

270-271

4.99

*1 x 8 V 4 x 6Vs*

270-272

5.99

3VKSX 4V4 x 4Vs"

270-273

6.99

3Vi**8V4x0Ve"

270-274

7.99

1 20,000 Ohms
Per Volt DC
Sensitivity
• With Leads
And Manual

Buy now and get this accurate Micronta® multitester
at 43% off! Features a big 4" mirrored scale, “output”
jack to measure AC signals present in DC circuits.
Measures 0 to 1200 volts DC in seven ranges, 0 to
1200 volts AC in five ranges, 0 to 300 milliamps DC
current in four ranges, resistance in four ranges, and
- 20 to + 63 dB in five ranges. 5 V 2 x 3 7 /e x 1 V 2 ". Re-
quires “AA” battery. 22-202 Sale 15.95

MCI 330 Video Detector. 3rd IF, detector,
video and AFC buffers. High linearity.
10-24VDC. 8-pin w/specs. 276-1757 . . 2.29
MCI 350 Universal IF Amp With AGC. For
radio and TV circuits. Usable to beyond 60

MHz. 8-pin w/specs. 276-1758 1.99

MCI 358/CA3065 FM Detector. IF amp, lim-
iter, FM detector, electronic volume attenua-
tor and audio driver. For 100 kHz-5.5 MHz
IFs, 14-pin w/specs. 276-1759 1.79

Ceramic TV-Sound Filters

NEW!

L.„ 6 g«

Replace Costly Transformers
• Pretuned— No Peaking or Tweaking !

SFE4.5MB. Use in place of 4.5 MHz sound
take-off transformer. 3 db bandwidth: 105

kHz, typ. 272-1304 69$

CDA4.5MD3 Discriminator. This differential
peak detector works great with our FM de-
tector 1C #276-1759, above.

274-1305 79$

10 % |RD Capacitors

A. NEW!

T r 59*

1C pin spacing. 63WVDC

.01 pF. 272-110 590

.1 pF. 272-111 690

.47 pF. 272-112 890

Horizontal Output

795

TO-3 Case

2SC1308. Rugged NPN transistor
is exact replacement in many 19"
color TVs. Servicemen— keep sev-
eral on handl 276-2055 7.95

3£DT Toggle Switch

349 Mini Size

Contacts rated 6
amps at 125VAC. V 4 "
mounting hole. With
hardware.

275-661 3.49

Tri-Color LED

-|39

Ideal Status
Indicator

Micro 5VDC
Relay

2 49 “.s

Ideal for crowded PC boards.

SPDT contacts: 1 amp at 125VAC.
55-ohm coil, .100" pin spacing.

275-240 2.49

Portable Solar Panel

Sale! Program Books for Your TRS-80

\ 39% Off I '

Your Choice Only <

Reg. 7.95

488

Computer Games. Contains listings for over 25 fun-filled game programs
for TRS-80 Level II BASIC. Selections include Blackjack, Poker, Tennis,
Tic-Tac-Toe, Escape, Golf, Basketball, Psycho, Star Trek, Biorhythm, Poem

and more. 151 pages. 62-2068 Sale 4.88

Using the TRS-80 in Your Home. Listings for over 75 practical programs
in Level II BASIC including finance, analysis, games, scheduling, lists and
much more. 330 pages. 62-2069 Sale 4.88

Fun Sounds Made
Easy!

XC-5491 . Glows red on
DC, green on reverse DC,
yellow on ACI 2.2V at 25
milliamps, typical.

276-035 1.39

Electret Element

99*

H/-F/

Response

Omnidirectional, PC mountable. 20
to 15 kHz ±4 dB. 2-10VDC, only 1
milliamp current drain.

270-090 New Low Price 99$

D-Sub 25 Connectors

2495

Radio Shack Exclusive!

Switchable 6 or 12VDC output. 32
full-spec cells produce approxi-
mately V 2 watt of “free” power.

277-1250 24.95

nesisior r

Resistor Networks

NEW!

89® Each

1C Lead Spacing

Five V4-watt resistors in one pack-
age. Ideal for digital pull up, LED
current limiting. 470-Ohm,

271-095. 1000-Ohm, 271-096.
lOk-Ohm, 271-097.

16-Pin DIP With Data

SN94281. Just add a speaker and
a few parts to make amazing
sounds. Heart of a rewarding pro-
ject— try it! 276-1767 2.49

Solder type. Perfect for computer
interfacing and making your own
RS-232 cables and extension cords.

El Male. 276-1547 2.99

IS Optional Hood.

276-1549 1.99

IS Female. 276-1548 3.99

A DIVISION OF TANDY CORPORATION

Radio /hack

Retail prices may vary at individual stores and dealers

OVER 8700 LOCATIONS WORLDWIDE

109

CIRCLE 86 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

110

CPU'S &
SUPPORT
CHIPS

8251

8253

8238

8279-5

8255

4.50

5.95

3.95

6.95

4.50

SCR's

1.5A 6A 35A

110A

TRIAC's |

PRV 1A 10A 25A \ ■

8039 6.95

8257 (AM9517)

7.95

100

.35

.40

1.40

100

■35

.60

1.40

8060A 2.75

8085A 5.75

8088 29.95

8259

8355

5.95

12.95

200

■40

.50

1.80

9.00

200

.50

.80

1.90

6502

5.75

400

.60

.70

2.40

12.00

400

.70

1.00

2.60

AMD 2901 8.95
8202 19.95

8212 1.80

ft? 14 3.H1

Z80ACPU
Z80B CPU
Z80AS10
Z80AP10

4.75

12.95

10.95

4.95

600

1.00

3.60

15.00

600

1.00

1.20

3.60

8216

8224

8155

8156
8237
8748

1.75

2.25

3.50

5.50

Z80CTCA 6.75

TMS9927NL 9.95
8275 16.95

12.95

13.95
2.50

2.95
2.95

INTER

FACE

DRIVERS

C/MOS

8755 19.95

SHIFT

REGISTERS

MM1402
MM1403

8130
8830

8131

MM1404

MM5013

MM5055

MM5056

MM5057

MM5060

1.75

2.50

ROM's

DISC

Controllers

1771.. 16.50

1793.. 35.00

1795.. 45.00

1797.. 45.00
D765C 16.95

RAM's

2.50
2.50
2.50
2.50
2.00
2.00
MM5307 7.95
BR1941L 8.95
CRT503718.95
MM5369 2.50
TR1602B 3.96

2708 2.95 21L02-3

2716 + 5V 3.50 2111AL
2732
2732A-2
2532
2764
82S23
82S115
(6381)

82S129
82S130

.70

1.95

5.95 2114L-3

15.95 2147-3 4.95

7.95 TMS3409 1.75

9.95 MK4008P 1.35

1.95 MK4027-3 1.75

4.00 TMS4050NL 2.95

1.95 MK4096-11 1.25

1.95 4116-3 1.10

1.95 4116-15 1.50

3.00 5101 E 2.95

AM9214C 2.95 Z61044

8256-5 1.25 6116-3

74S387 1.75 8264(4164-2) 5.75

74S474 3.96 58725

(MK4802) 5.95
3242 6.00

2.50

5.50

NO. 30 WIRE
WRAP WIRE
SINGLE
STRAND
100'. . $1.40

CRYSTALS

2.000 6.144
■3.000 8.000
3.579 10.000

4.000 18.000

5.000 18.432

6.000 20.000

2.95 ea.

4010

4011

4012

4013

4014

4015

4016

4017

4018

4019

4020

4021

4022

4023

4024

4025

- 1.75

- .75

- .65

4053

4060

4066

4070

4071

4072

4076

4077

4081

4082
4093
4099
4501

4510

4511

4514

4515

4516
4518
4520
4528

- .80

- .75

- 1.25

- 1.50

- .75

4583 - 90

4585 - 75

74C00 - .27

74C02 - .27

74C04 - .35

74C08 - .30

74C10 - .27

74C14 - .55

74C20 - .27

74C32 - .39

74C42 - 1.00
74C74 - .50

74C76 - .70

74C85 - 1.40
74C86 - .39

74C90 - .90

74C93 - .50

74C154 - 2.50
74C157 - 1.75
74C160 - 1.20
74C161 - 1.15
74C163 - 1.15
74C173 - .75

74C174 -1.15
74C175 - 1.19
74C192 - 1.30
74C901 - .39

74C902 - .70

74C914 - 1.75
74C921 - 3.95
74C83 - 1.25

50 PIN RIBBON CONNECTORS

. . . $2.25

40 PIN RIBBON CABLE CONN

. . . $2.00

34 PIN RIBBON CABLE CONN

. . . $2.00

26 PIN RIBBON CABLE CONN

...$1.75

20 PIN RIBBON CABLE CONN

. . .$1.50

10 PIN RIBBON CABLE CONN

...$1.00

2N3820 P FET

. $ .45

2N 5457 N FET

. $ .45

2N2646 UJT

. $ .45

ER 900 TRIGGER DIODES

4/$1 .00

2N 6028 PROG. UJT

. $ .65

DISC CAPACITORS

.1UF 16V 10 $1.00

100/ $8.00

.01 UF 35V 16 $1 00

100/$5.00

4639

- 1.25

74S SERIES 74S85

1.25

74S163

1.40

74SOO

.30

74S86

.60

74S169

1.75

74S02

.30

74S89

1.90

74S174

1.40

74S03

.30

74S112

.85

74S175

1.40

74S04

.40

74S133

.50

74S182

1.75

74S05

.45

74S135

1.10

74S194

1.10

74S08

.40

74S138

1.25

74S240

1.00

74S10

.30

74S139

1.10

74S241

1.50

74S11

.35

74S140

1.70

74S257

1.30

74S15

.40

74S151

1.25

74S258

1.30

74S20

.40

74S153

.95

74S260

1.50

74S30

.40

74S157

1.25

74S280

1.75

74S32

.40

74S158

1.25

74S373

2.25

74S74

.70

74S161

1.75

74S374

1.75

PRINTED CIRCUIT BOARD

4' x 6" DOUBLE SIDED EPOXY BOARDED V, ."THICK
$-60ea 5/$2.60

TOGGLE 1060 - SPDT “ 80

2060 - DPDT — 1.20

SWITCHES 206P - DPDT — CENTER OFF $1.40

IN4148 (IN914) 15/1.00

L141 1 -IR DETECTOR 3/$1 .00

FP 100 PHOTO TRANS $ .50

RED LED's .2" 8/$1.00

YEL, GREEN or AMBER LARGE LED's .2". . 6/$1 .00

RED-GREEN BIPOLAR LED $ .90

RED-YELLOW BIPOLAR LED $ .90

MLED92IR LED $ .40

MRD14B PHOTO DARL. XTOR $ .50

MCT2 OPTO ISOLATORS $ .40

4N26 OPTO ISOLATOR $ .40

1 WATT ZENERS: 3.3, 4.7, 5.1, 5.6, 6.8,

8.2, 9.1, 10, 12, 15, 18, or 22V 6/$1.00

LINEAR CIRCUITS

DAQ08EQ - 3.75 LF356 - 1.00 747 - .50

TL062 CP - .95 LM358 - .50 CA758 - 1.75

TL064 CN - 1.50 LM361 - 1.75 LM1310 - 1.60

TL084 - 1.50 LM370 - 1.60 1456 - .80

LM201 - .75 LM377 - 1.60 1458 - .50

LM301/748 - .30 LM380 - .86
LM307 -
LM308 -
LM310 -

1.10
LM311 - .50
LM318 - .75
LM319 - .95
LM324 - .55
LM339 - .65
LM348 - .90
LF351 - .56
LF353 - .90
LF355 - .90

LM1808 - 1.75
LM383 - 1.90 LM2901 - .96
LM386 - .85 CA3018 - 1.95

LM387 - 1.25 CA3078AT - 1.50
LM393 - .75 CA3086 - .75

LM555 - .34 AD2700LD - 4.95
LM556 - .65 CA3140 - 1.00

565 - .95 3900 - .45

4136 - .85
N5596A - 1.50
D6303B - 1.75
8038CC - 3.90
LM13080 - .95
CA3089E - 1.75

567 - .85

709 - .25

710 - .45
711CH - .40
741 CV - .40

FULL WAVE BRIDGE

PRV I 2A I 6A I 2SA

S.P. 1200 ohm coil
.75

D.P. 400 ohm coil
.95

FLAT

DIP SWITCHES

RIBBON

CTS 206- 4

4 POSITION .75

CABLE

CTS 206- 7

7 POSITION .95

GRAY

CTS 206- 8

8 POSITION .95

28 gauge

CTS 206-10

10 POSITION 1.25

26 conductor

DIP

.60/ft

SOCKETS 20 PIN .25

40 conductor

8 PIN .10

22 PIN .25

. 90/ft

14 PIN .12

24 PIN .25

50 conductor

16 PIN .15

28 PIN .35

1.00

18 PIN .20

40 PIN .40

WIRE WRAP

14PIN

.45

16 PIN

—

.50

18 PIN

—

.65

20 PIN

—

.90

24 PIN

—

1.10

28 PIN

—

1.25

40 PIN

—

1.50

DB CONNECTORS

DB9P - $2.00 DB25P - $2.40
DB9S - 3.00 DB25S - 3.20
HOODS- 1.10 HOODS- 1.10

EPOXY GLASS VECTOR BOARD

1/16" thick with 1/10" spacing

4y 2 " X 6y 2 " $1 .95

14 PIN HEADERS

. 3/$1.00

16 PIN HEADERS

. . . .40

24 PIN HEADERS

... .75

40 PIN HEADERS

... 1.10

50 PIN EDGEBOARD CONN. .

... 3.95

26 PIN EDGEBOARD CONN..

... 2.50

50 PIN ANGLE CONN

... 3.95

TRANSISTOR SPECIALS

2N1307PNPGETO-5 $ .40

2N404A PNP GE TO-5 3/$1 .00

HEP G6014 — PNP GETO-3 $ .85

TIP 111 $.50 TIP 146 $1.35

2N6233-NPN SWITCHING POWER $1.95

MRF-8004 CM RF TRANSISTOR NPN $ .75

2N3772NPN SiTO-3 $1.00

2N4908 PNP SiTO-3 $1.00

TIP 2955 PNP Si $ .70

2N2222 NPN Si TO-18 7/$1 .00

2N2907 PNP Si TO-18 6/$1.00

2N3055 NPN SiTO-3 $ .60

2N3904 NPN Si TO-92 7/$1.00

2N3906 PNP Si TO-92 7/$1.00

2N6109 PNP Si TO-220 $ .56

TIP 31 B NPN Si TO-220 $ 40

TIP 32B PNP Si TO-220 $ 40

TIP 34 PNP SI $ .95

TIP 121 PNP Si U84 $ .60

TIP 141 NPN Si U97 $1.00

BU205 $1.75

DPS2000 - DUAL POWER DARL $3.95

MJE3056T $ .60

TTLIC SERIES

7400 .17

7401 .17

7402 .17

7403 .17

7404 .24

7405 .24

7406 .28

7407 .28

7408 .24

7409 .18

7410 .17

7411 .22

7412 .30

7413 .35

7414 .45

7416 .25

7417 .25
7420 .17

7425 .25

7426 .25

7427 .25
7430 .17
7432 .27

7437 .27

7438 .27

7440 .17

7441 .75

7442 .45

7445 .65

7446 .65

7447 .65

7448 .65
7450 .17

7472 .30

7473 .35

7474 .32

7475 .40

7476 .35

7480 .45

7483 .50

7485 .55

7486 .35

7489 1.60

7490 .35

7491 .45

7492 .45

7493 .35

7494 .60

7495 .55

7496 .60
74107 .30
74116 1.50

74121 .29

74122 .39

74123 .42
74126 .45
74145 .60
74148 1.10

74150 1.10

74151 .50

74153 .40

75154 1.10
74155 .50

74157 .50

74160 .85

74161 .65

74612

74163

74164

74165

74166
74170

74173

74174

74175

74176
74180
74182

74190

74191

74193

74194

74195

74196
74221
74273
74279
74298
74365
74367
74390

75324

75325
75492

9601

9602
8T26
8T97
8T98

74LS SERIES

SILICON POWER RECTIFIERS

PRV 1A

3A 12A 50 A 125A

240A

100 05

.14

.35 .90 4.25

6.00

200 06

_17

•50 1.30 5.25

9 00

400 .09

.65 1.50 • 6.50

1200

600 .11

.30

.80 2.00 8.50

15.00

800 13

.35 1.00 2.50 10.50

18.00

1000 .20

.45 1

.25 3.00 12.50

26.00

REGULATORS

LM338K

$5.75

323K I LA 1405) . .

. . $T75

LM317T

$1.00

LM305G

. . $ .75

78L05, 78L12,

$ .40

340T-5, 6, 8, 9, 12,

723

$ .50

15, 18 or 24V .

. .$ .75 I

1 320T5, 12, 15or24 $ .85

LAS1412 + 12V

| LM337T

....$1.95

3 A

. . $3.95 |

1 TANTALUM CAPACITORS f

.22UF35V

5/$1.00

15UF16V 3/$1.00 I

.47UF35V

5/$1.00

30UF6V 5/$1.00 I

.68UF35V

5/$1.00

33UF15V

$ .50

1UF20V

5/$1.00

47UF20V

$ .85

2.2UF20V

5/$1.00

68UF16V

$1.00

3.3UF20V

4/$1.00

120UF6V

$ .75

4.7UF35V

4/$1 .00

200UF20V

$1.75

6.8UF20V

4/$1.00

150UF16V

$1.30

10UF20V

- $ .40

330UF10V

$1.75

22UF 10V

- $ .30

74LS00 .28
74LS01 .28
74LS02 .33
74LS03 33
74LS04 .35
74LS05 .38
74LS08 .35
74LS09 .35
74LS10 .35
74LS11 .35
74LS12 .35
74LS13 .45
74LS14 .50
74LS15 .50
74LS20 .35
74LS21 .35
74LS22 .35
74LS26 .45
74LS27 .40
74LS28 .50
74LS30 .35
74LS32 .40
74LS37 .40
74LS38 .40
74LS40 .35
74LS42 .55
74LS47 .80
74LS51 .35
74LS54 .35
74LS73 .45
74LS74 .45
74LS75 .45
74LS76 .45
74LS83 .80
74LS85 90
74LS86 .60
74LS90 .55
74LS92 .70
74LS93 .70
74LS96 .80
74LS107 .45

74LS109 .45

74LS112 .50

74LS113 .60

74LS114 .65

74LS123 .85
74LS125 .60

74LS126 .60

74LS132 .75

74LS136 .56

74LS137 .95

74LS138 .70

74LS139 .70

74LS147 1.95
74LS151 .70

74LS153 .70

74LS154 2.40
74LS155 .80

74LS156 .80
74LS157 .80

74LS158 .80

74LS160 .90

74LS161 .90

74LS162 .90

74LS163 .90

74LS164 .90

74LS165 .90

74LS166 1.90
74LS169 2.50
74LS170 1.90
74LS173 .90
74LS174 .90

74LS175 .90

74LS181 1.95
74LS190 .90

74LS191 .90

74LS192 .90

74LS193 .90

74LS194 .90

74LS195 .90
74LS196 .90

74LS197 .90

74LS.221 .10

74LS240 1.10
74LS241 1.10
74LS242 1.10
74LS243 1.10
74LS244 1.30
74LS245 1.75
74LS446 .95

74LS247 .90

74LS248 1.10
74LS251 .70

74LS253 .70
74LS257 .70

74LS258 .80

74LS259 1.00
74LS266 .70

74LS273 1.15
74LS279 .60

74LS280 1.80
74LS283 .80

74LS290 .90

74LS293 .90

741S298 .90

74LS320 2.00
74LS323 3.50
74LS365 .70

74LS366 .70

74LS367 .70

74LS368 .70

74LS373 1.20
74LS374 1.20
74LS377 1.50
74LS386 .60

74LS390 1.10
74LS393 1.10
74LS398 2.50
74LS625 1.75
74LS668 1.50
74LS670 1.20
74LS682 3.00
81LS97 1.20

81LS98 1.20

MULTI TURN TRIM POTS

50 OHM 5K
100 OHM 10K
500 OHM 50K 3/$2.00
1000 OHM 500K

POSTAGE RATES
ADD 10% FOR ORDERS UNDER $25.00
ADD 5% FOR ORDERS BETWEEN $25.00 & $50.00
ADD 3% FOR ORDERS ABOVE $50.00

TERMS: FOB CAMBRIDGE. MASS. SEND CHECK
OR MONEY ORDER. MINIMUM TELEPHONE.
COD. PURCHASE ORDER OR CHARGE $20.00
MINIMUM MAIL ORDER $5.00.

SEND $.25 FOR OUR CATALOG
FEATURING TRANSISTORS &
RECTIFIERS. 145 HAMPSHIRE
ST . CAMBRIDGE. MASS 02139

SOLID STATE SALES

P.O. BOX 74 D

SOMERVILLE, MASS. 02143

TEL (617) 547-7053

WE SHIP OVER OVER 95%

OF OUR ORDERS WITHIN
24 HOURS OF RECEIPT

TOLL FREE 1-800-343-5230

FOR ORDERS ONLY

ACTIVE

RECEIVING

ANTENNA

Gives excellent reception,
50 KHz to 30 MHz.

New MFJ-1024 Active Receiving
Antenna mounts outdoors away from
electrical noise for maximum signal.

Gives excellent reception of 50 KHz
to 30 MHz signals. Equivalent to wire
hundreds of feet long. Use any SWL,
MW, BCB, VLF or Ham receiver.

High dynamic range RF amplifier. 54
in. wnip. 50 foot coax. 20 dB attenuator
prevents receiver overload. Switch be-
tween two receivers. Select auxiliary or
.active antenna. Gain control. “ON”
LED. Remote unit, 3x2x4 in. Control,
^6x2x5 in. 12 VDC or 110 VAC with
optional adapter,
MFJ-1312, $9.95.

(+$4.00

129

Order from MFJ and try it. If not delighted,
return within 30 days for refund (less shipping).
One year unconditional guarantee.

Order today. Call TOLL FREE 800-647-1800.
Charge VISA, MC. Or mail check, money order.
Write for free catalog. Over 100 products.

CALL TOLL FREE 800-647-1800

Call 601-323-5869 in Miss., outside continental
USA, tech/order/repair info. TELEX 53-4590.

Ue I ENTERPRISES,

KYirU INCORPORATED

^Box 494, Mississippi State, MS 39762 „

CIRCLE 66 ON FREE INFORMATION CARD

Free Buyers Guide

pages of the latest in components, tools
and instruments - a must for DESIGNERS,
instructors and maintenance engineers.

NEW ZENITH ZXM 121

High legibility 1 2” green phosphor monitor.

1 5 Mhz bandwidth,

40 or 80 character

selectable full compotability . . $99.95

IC’S

3WS

-twces

PRICES

7808

T33

2200 40VDC UF

rw~

7815

T30

lOOO UF 16VDC

—

1330

370 '35' V

■ 1.09

” 1350

T35

220 MFD 25V

30“

1358

230

TM MFD 16V

70“

”386-8

2313

io MFD 50V

36“

4558

230

4.7 MFD 35V

36“

1 4 58

1.25

1 MFD 50V

36“

RESISTOR BUYOUT

MOST STANDARD VALUES
’A WATT 5% RESISTORS 1 OHM TO 10 MEG. OHM
2 K MIN. BUY 1 K MIN. PER VALUE
$6.50 Per i,qqq

UHF/VHF Conversion
Kit - with

Genuine Mitsumi .

Tuner $119.95

CALL OUR HOT LINES
IN CALIF. (714) 527-2554
OUTSIDE CAL (800) 854-8660

SCR ELECTRONICS CENTER

5303 Lincoln Ave., Cypress. CA 90630

CIRCLE 23 ON FREE INFORMATION CARD

CIRCLE 25 ON FREE INFORMATION CARD

WE HAVE QUALITY PARTS, DISCOUNT PRICES AND FAST SHIPPING

TRANSFORMERS

120 volt

primaries

5.6 VOLTS at 750 MA

$3.00

6 VOLTS at 150 MA

$1.25

16.5 V. at 3 AMPS

$6.50

18 V at 650 MA

$3£0

18 VOLTS at 1 AMP

$4.50

18 V.C.T. at 2 AMP

$5.50

24 VOLTS at 250 MA

$2.50

24 VCT at 1 AMP

$4.50

42 V.C.T. at 1.2 AMP

$4.50

DC WALL
TRANSFORMER

ALL ARE 115 VAC
PLUG IN

4 VDC at 70 MA
9 VDC at 225 MA

$2.50
$3.00

16.5 VAC at 10 VA $3.50
17 VAC at 500 MA $4.00
22 VDC at 60 MA $2.50

VARACTOR
B DIODE

If MV2205 3 FOR $1.00

I 16 PF 100 FOR $30.00

BB-103 3 for $1.00'

33 PF 100 FOR $30.00

BLACK PLASTIC
CASE

BLACK PLASTIC ENCLOSURE
ADJUSTABLE HEIGHT FROM
1.63" TO 2.93"; WIDTH
6.85"; DEPTH 8". BUILT-IN
STAND OFFS FOR P.C.
BOARDS . . FRONT AND BACK
PANELS NOT INCLUDED . .

$5.25 PER CASE

2K 10 TURN

MULTI-TURN POT
SPECTROL
#MOD 534-7161

$5.00 EACH

MIKE

CONNECTOR

5 CONDUCTOR IN-LINE PLUG
AND CHASSIS MOUNT JACK.
TWIST LOCK STYLE, SAME AS
SWITCHCRAFT 12CL5M.

$2.50 PER SET

CRYSTALS

CASE STYLE HC33/U

COLORBURST
‘ ”” ~ 3579.545 KC

$3.50 EACH $1.00 EACH

2 CHANNEL LIGHT ORGAN

EASILY HOOKS INTO STEREO SPEAKERS
AND ALLOWS 110 VAC LIGHTS TO DANCE
WITH MUSIC. TWO SEPARATE 110 VAC
OUTPUTS FOR HIGH AND LOW FREQUENCY
AUDIO SIGNALS. USE TWO ORGANS FOR
STEREO...

$6.50 PER UNIT

COLOR LIGHT STRING AVAILABLE $1 .75 EA

T.V. GAME
SWITCH

RCA PLUG or
300 OHM IN

300 ohms
OUT

$2.75 EACH

S.C.R.

0.8 AMPS 30 VOLTS

5 for $1.00
4 AMPS 200 VOLTS

656 EACH

4 AMPS 500 VOLTS

854 EACH

TRIAC

6 AMPS 400 VOLTS

756 EACH

TRANSISTORS

2N706

2N2222A

PN2222

2N2904

2N2905

2N2907

MJ3030

2N3055

2N3565

2N3904

2N3906

2N4401

2N4403

2N4898

D43C8

D44C2

TIP 31

TIP 32

TIP 121

TIP 126

5 for $1.00
4 for $1.00
8 for $1.00
4 for $1.00
4 for $1.00

4 for $1.00

$2.50

$1.00

5 for $1.00
5 for $1.00
5 for $1.00
5 for $1.00

$1.50
2 for $1.00
.75
.75
.75
.75
.75

MICROWAVE
TRANSISTOR

MRF 901 REDUCED TO
N.P.N. SILICON $2.00 EACH

LIGHTS

GRAIN OF WHEAT
T1 SIZE

.125" DIA. (3.15mm)

3 to 6 VOLTS 3 for $1.00

Rated; 55ma @ 5 VOLTS

6 to 12 VOLTS 3 for $1.00

Rated: 55ma @ 8 VOLTS

12 to 24 VOLTS 3 for $1.00

Rated: 45ma @ 14 VOLTS

T1 SIZE
WITH WIRE LEADS

3 to 6 VOLTS 2 for $1.00

Rated: 55ma @ 5 VOLTS

6 to 12 VOLTS 2 for $1.00

Rated: 55ma @ 8 VOLTS

12 to 24 VOLTS 2 for $1.00

Rated: 45ma @ 14 VOLTS

T1- 3/4 SIZE
WITH

WIRE LEADS

163" DIA. (4.14mm)

3 to 6 VOLTS 2 for $1.00

Rated: 45ma @ 6 VOLTS

6 to 12 VOLTS 2 for $1.00

Rated: 55ma @ 8 VOLTS

12 to 24 VOLTS 2 for $1.00

Rated: 45ma @ 14 VOLTS

NEON W/ RESISTOR

OPERATION

7 for $1.00 FROM 120 VOLT

120V INDICATOR

NEON INDICATOR. RATED
120 V 1/3 W. MOUNTS IN
5/16" HOLE . . . RED LENS.
756 EACH
10 FOR $7.00
100 FOR $65.00

1 2 VOLT A.C. POWER UNIT

THIS UNIT CONSISTS OF A 12 VOLT 2 AMP
TRANSFORMER. 1 AMP CIRCUIT BREAKER,
4 PRONG CINCH JONES SOCKET AND A 3
WIRE A.C. CORD ALL MOUNTED IN AN
ATTRACTIVE 4Vk" x 5V4" x 3" CHASSIS BOX.
GOOD FOR PARTS OR A NICE START FOR

D C. POWER SUPPLY.

$8.50 PER UNIT

CO-AX SWITCH
(A/B SWITCH)

75 ohms IN
TWO

75 ohms OUT

$3.50 EACH

METERS

0 - 20 V.D.C.

0 -20 VDC FULL SCALE
FACEPLATE
BATTERY TEST
SET-UP AS
INDICATOR
$5.50 EACH

1 MA

2 5/16" SQUARE
PANEL METER
MOUNTS IN
2 1/8" HOLE

$5.50 EACH

0 - 15 V.D.C.

THIS 2-1/4"
SQUARE METER
MEASURES
0-15 VDC.

$4.50 EACH

METAL OXIDE
VARISTOR

2 FOR
$1.50

G.E. # V82ZA12
50 VOLTS, NOMINAL D.C.
VOLTAGE. 5/8" DIAMETER.

LINE CORDS

TWO WIRE

6' 18ga TWO WIRE

3 FOR $1.00

THREE WIRE

18 INCH 18ga THREE WIRE

2 for $1.00

8 FOOT 18ga THREE WIRE

$2.00 EACH

SWITCHES

MINI-PUSH BUTTON

S.P.S.T. MOMENTARY
NORMALLY OPEN
1/4" BUSHING

354 EACH
10 FOR $3.25
100 FOR $30.00
SPECIFY COLOR:

RED, BLACK,

WHITE, GREEN. YELLOW.

KEY SWITCH

S.P.S.T.

4 AMPS @ 125 VAC
KEY REMOVES BOTH
POSITIONS $3.50 EA

LIGHTED
PUSH BUTTON

* RED LIGHTED 120 VAC
10 AMP. S.P.S.T.
“POWER” PRINTED ON
FACE. MOUNTS IN
7/8" SQUARE HOLE . .
$1.50 EA 10 FOR $13.50

FREE! fR £E'. f r ee! SEND FOR OUR NEW 40 PAGE CATALOG fr ee/ f REe

-WAY CAR STEREO SPEAKER
SYSTEM

THESE SPEAKERS COME IN HEAT
RESISTANT ABS PLASTIC CABINETS.
IDEAL FOR CAR INTERIORS WHERE
HEAT CHANGE OCCURS . . .

POWER RATING: 15 WATT NOM.

45 WATT MAX.

EACH SYSTEM CONTAINS A 4 INCH
10 OZ. WOOFER AND 2 INCH TWEETER

SPECIAL PRICE $36.00 PER PAIR

KEY

ASSEMBLY

5 KEY

CONTAINS 5 SINGLE-POLE
NORMALLY OPEN SWITCHES.
MEASURES 3 3/4" LONG

6 KEY

$1.25
EACH

CONTAINS 6 SINGLE-POLE
NORMALLY OPEN SWITCHES.
MEASURES 4 1/4" LONG.

SLIDE a POTS

9 E x POI

100K linear tape

2" LONG

1 5/8" TRAVEL 756 EACH

500K linear taper

2 7/8" LONG

1 3/4" TRAVEL 754 EACH

DUAL 100K

audio taper

3 1/2" LONG

2 1/2" TRAVEL. $1.50 EACH

POWER SUPPLY W/ PRE-AMP

THIS SUPPLY WAS USED TO POWER
AN 8 TRACK/CASSETTE UNIT. IT
WILL SUPPLY APPROX. 18 VDC AND
INCLUDES A SMALL PRE-AMP TO
BOOST SIGNAL LEVEL.

RCA PLUGS FOR LINE IN/OUT.

$4.50 EACH

RELAYS

6 VDC RELAY

MINIATURE D.P.D.T.

3 AMP CONTACTS
FUJUITSU # FBR321D006
$1.75 EA 10/16.00

MINIATURE
6 VDC RELAY

SUPER SMALL
SPDT RELAY;
GOLD COBALT
CONTACTS.
RATED 1 AMP AT 30 VDC;
HIGHLY SENSITIVE, TTL
DIRECT DRIVE POSSIBLE,
OPERATES FROM 4.3 TO
6 V, COIL RES. 220 OHM.

1 3/16" * 13/32" * 7/16"
AROMAT # RSD-6V

$1.50 EACH

10 FOR $13.50

13 VDC RELAY

CONTACT: S.P.N.C.
10 AMP @ 120 VAC
ENERGIZE COIL TO
OPEN CONTACT . . .
J30IL: 13 VDC 650 OHMS
PRICE $1.00 EACH

l PDT RELAY

• 14 pin style

• 3 amp contacts

• 24 volt d.c. or
120 volt a.c. coil

• Used but fully tested
$1.70 EACH
specify coil voltage
LARGE QUANTITIES AVAILABLE

SOCKETS FOR RELAY 50* Mch

COMPUTER

GRADE

CAPACITORS

1700 mfd. 150 VDC $2.00

2 1/2" DIA x 4 3/4" HIGH^a*.

3,600 mfd.

40VDC $1.00

1 3/8" DIA. x 3" HIGH

6,400 mfd.

60 VDC $2.50 U

1 3/8" DIA. x 4 1/4" HIGH

18.000 mfd. 75 VDC $4.00

2 1/2" DIA. x 4 1/2" HIGH

22.000 mfd. 15 VDC

2" DIA. x 2 1/2" HIGH $2.00

22.000 mfd. 40 VDC
2" DIA. x 6" HIGH $3.00

24.000 mfd. 30 VDC

3/4" DIA. x 4" HIGH $3.50

31.000 mfd. 15 VDC

1 3/4" DIA. x 4" HIGH $2.50

72.000 mfd. 15 VDC

2" DIA. x 4" HIGH $3.50

180.000 mfd. at 6V

2 1/2" DIA. x 4 1/2" HIGH $1.50
CLAMPS TO FIT CAPACITORS SO* ••

EDGE

CONNECTORS

15 PIN GOLD

SOLDER EYELET $1.75 EACH

15/30 GOLD

SOLDER EYELET $2.00 EACH

18/36 GOLD

SOLDER EYELET $2.00 EACH

22/44 GOLD

SOLDERTAIL (P.C. STYLE)
$2.50 EA 10 FOR $22.50

SOLID STATE
RELAY

CONTROL:

3-32 VDC
LOAD: 10 AMP

140 VAC $9.50 EACH

MINIATURE TOGGLE SWITCHES

ALL ARE

S.P.D.T.
(on-on) I

P.C. STYLE, J
NON-THREADEDl
BUSHING. CS
75* EACH ■ ii
10 FOR $7.00 JlJ

S.P.D.T.
(on-off-on) I

NON-THREADEDJI
BUSHING. CSL
P.C. STYLE ■ m
75* EACH Ypr?

10 FOR $7.00 * V

RATED 5 AMPS I

S.P.D.T.
(on-on)

SOLDER LUG
TERMINALS.

$1.00 EACH

10 FOR $9.00 1
100 FOR $80. C

S.P.D.T.
(on-on)

P.C. LUGS,
THREADED |
BUSHING.

$1.00 EACH 1
10 FOR $9.00V
100 FOR $80.00

J 125 VAC
S.P.D.T.
(on-off-on) m

SOLDER LUG
TERMINALS.

$1.00 EACH
10 FOR $9.00
100 FOR $80.00

D.P.D.T.
(on-on)

SOLDER LUG .
TERMINALS.

$2.00 EACH
10 FOR $19.00 *
100 FOR $180.00

L.E.D.’S

STANDARD JUMBO
DIFFUSED
RED 10 FOR $1.50
QREEN 10 FOR $2.00
YELLOW 10 FOR $2.00

f \ FLASHER LED
^ 5 VOLT OPERATION
■ RED JUMBO SIZE
$1.00 EACH

I BIPOLAR LED

II 2 FOR $1.70

SUB-MINI LED

.079" x .098" 20 MA AT 1.75V

RED 10 FOR $1.00
200 FOR $18.00
QREEN 10 FOR $1.50

LED HOLDERS

TWO PIECE HOLDER A
FOR JUMBO LED w £?
10 FOR 656 200 FOR $10.00

PHOTO-FLASH

CAPACITORS

35 MFD 330 VOLT

170 MFD 330 VOLT

1 1/8" x 7/8"

2 FOR $1.50 10 FOR $7.00

750 MFD 330 VOLT

2" HIGH x 1 1/4" DIA.
$1.25 EACH 10 FOR $11. 00

TOLL FREE ORDERS ONLY
1-800-826-5432
(ORDER ONLY)

ALASKA. HAWAII. CALIF
OR INFORMATION
(213) 380 8000

QUANTITIES LIMITED
MINIMUM ORDER S10.00
USA: S2.50 SHIPPING
FOREIGN ORDERS:
INCLUDE SUFFICIENT
SHIPPING

CALIF. RES. ADD 6’.

NO C O D. 1

CIRCLE 73 ON FREE INFORMATION CARD

111

JULY 1983

RADIO-ELECTRONICS

112

[ mm\

Part No. ••Pint Prie»

** Number of Pint of each I.C. |
tor uty Socket purchau

SN7400N

SN7401N

SN7402N

SN7403N

SN7404N

SN7405N

SN7406N

SN7407N

SN7408N

SN7409N

SN7410N

SN7411N

SN7412N

SN7413N

SN7414N

SN7416N

SN7417N

SN7420N

SN7421N

SN7422N

SN7423N

SN7425N

SN7426N

SN7427N

SN7428N

SN7430N

SN7432N

SN7437N

SN7438N

SN7439N

SN7440N

SN7441N

SN7442N

SN7443N

SN7444N

SN7445N

SN7446N

SN7447N

SN7448N

SN7450N

SN7451N

SN7453N

SN7454N

SN7459A

SN7460N

SN7470N

74LSOO

74LS01

74LS02

74LS03

741S04

74LS05

74LS08

74LS09

74LS10

74LS11

74LS12

74LS13

74LS14

74LS15

74LS20

74LS21

74L322

74LS28

74LS27

74LS28

74LS30

74LS32

74LS33

74LS37

74LS38

74LS40

74LS42

74LS47

74LS48

74LS49

74LS51

74LS54

74LS55

74LS73

74LS74

74LS7S

74LS78

74LS83

74LS85

74LS86

74LS90

C04000 14 .29

CD4001 14 .29

CD4002 14 .29

C 04006 14 .89

C 04007 14 .29

C 04009 16 .39

CD4010 16 .39

CD4011 14 .29

C04012 14 .15

C 04013 14 .39

CD4014 16 79

CD4015 16 .39

C 04016 14 .39

C 040 17 16 .75

C 04018 16 .79

C 04019 16 .39

C 04020 16 .75

C 04021 16 .79

C 04022 16 .79

C 04023 14 .29

CD4024 14 .69

C 04025 14 .23

C 04026 16 2.49

CD4027 16 .45

C04028 16 .69

C04029 16 79

C04030 14 .39

C 04034 24 1.95

LC 04035 16 89

(More In Catalog)

Part No.

MICROPROCESSOR COMPONENTS Digitaiker

SN7472N 1

SN7473N 1

SN7474N 1

SN7475N 1

SN7476N 1

SN7479N 1

SN7480N 1

SN7482N 1

SN7483N 1

SN7485N 1

SN7486N 1

SN7489N 1

SN7490N 1

SN7491N 1

SN7492N 1

SN7493N 1

SN7494N 1

SN7495N 1

SN7496N 1

SN7497N 1

SN74100N 2
SN74104N 1
SN74105N 1
SN74107N 1
SN74109N 1
SN74116N 2
SN74121N 1
SN74122N 1
SN74123N 1
SN74125N 1
SN74126N 1
SN74132N 1
SN74136N 1
SN74141N 1
SN74142N 1
SN74143N 2
SN74144N 2
SN74145N 1
SN74147N 1
SN74148N 1
SN74150N 2
SN74151N 1
SN74152N 1
SN74153N 1
SN74154N 2
SN74155N 1

74S124

74S133

74S134

74S135

74S136

74S138

74S139

74S140

74S151

74S153

74S157

74S158

74S160

74S174

74S175

74S188*

74S194

74S195

74S196

74S240

74S241

74S242

20 2.25
20 2.25
14 2.49

CA3060N 16 3.25

CA3080E 8 .89

CA3081N 16 1.49

CA3082N 16 1.49

CA3083N 16 1.49

CA3086N 14 .69

CD— CMOS

CD4040
C04041
C04042
CD4043
CD4044
C04046
CD4047
C04048
CD4049
CD4050
CD4051
C 04052
C04053
CD4056
C04059
C04060
CD4066
C04068
CD4069
C04070
C04071
CD4072
C04073
C04075
C04076
C04078
C 04081
CD4082
CD4093

SN74156N

SN74157N

SN74160N

SN74161N

SN74162N

SN74163N

SN74164N

SN74165N

SN74166N

SN74167N

SN74170N

SN74172N

SN74173N

SN74174N

SN74175N

SN74176N

SN74177N

SN74179N

SN74180N

SN74181N

SN74182N

SN74184N

SN74185N

SN74190N

SN74191N

SN74192N

SN74193N

SN74194N

SN74195N

SN74196N

SN74197N

SN74198N

SN74199N

SN74221N

SN74251N

SN74276N

SN74279N

SN74283N

SN74284N

SN74285N

SN74365N

SN74366N

SN74367N

SN74368N

SN74390N

SN74393N

16 2.95
16 2.95
18 .55

74LS192

74LS193

74LS194

74LS195

74LS197

74LS221

74LS240

74LS241

74LS242

74LS243

74LS244

74LS245

74LS247

74LS248

74LS249

74LS251

74LS253

74LS257

74LS258

74LS280

74LS266

74LS273

74LS279

74LS283

741S290

74LS293

74LS298

74LS352

74LS353

74LS385

74LS366

74LS367

74LS368

74LS373

74LS374

74LS375

74LS386

74LS393

74LS399

74LS670

81LS95

81LS97

CD4098

CD4506

CD4507

CD4508

CD4510

CD4511

C04512

C 04514

C 04515 :

C 04516

C 04518

CD4519

C 04520

CD4526

C 04528

C 04529

CD4543

CD4562

CD4566

C 04583

CD4584

C 04723

CD4724

MCI 4409

MC14410

MC14411 i

MC14412

MC14419

MC14433 :

MC14538

MC14541 '

MICROPROCESSOR CHIPS

Part No. ♦•Pins Function Price

CDP1802 40 CPU $9.95

2650 40 MPU 14.95

IDM2901ADC 40 CPU -4-bit slice (Com. Temp. Gr.) 19.95

MCS6502 40 MPU w/Clock (65K bytes mem. ) 9.95

MC6802CP 40 MPU w/Clock and RAM 7.95

INS8035N-6 40 MPU— 8-bit (6MHz) 5.95

INS8039N-6 40 CPU-Sgl. chip8-bit(128bts. Ram) . . .5.95

INS8040N-6 40 CPU (256 bytes RAM) 5.95

INS8070N 40 CPU (64 bytes RAM) 11.95

INS8073N 40 CPU w/Basic Micro Interpreter 14.95

P8085A 40 CPU 5.95

— Z80, Z80A, Z80B, Z8000 SERIES

40 CPU (MK3880N)(780C) 2MHz $4.95

Z80-CTC 28 Counter Timer Circuit 5.95

Z80-DART 40 Dual Asynchronous Rec. /Trans .11.95

Z80-DMA 40 Direct Memory Access Circuit 1 5.95

Z 80-PI 0 40 Parallel I/O Interface Controller 5.95

Z80-S10/0 40 Serial I/O (TxCB and RxCB Bonded) .15.95

Z80-S10/1 40 Serial I/O (Lacks OTRB) 15.95

Z80-S10/2 40 Serial I/O (Lacks SYNCB) 15.95

Z80-S10/9 40 Serial I/O 15.95

Z80A 40 CPU (MK3880N-4)(780C-1)4MHz . .5.95

Z80A-CTC 28 Counter Timer Circuit 5.95'

Z80A-0ART 40 Dual Asynchronous Rec. /Trans 11.95

Z80A-DMA 40 Direct Memory Access Circuit 17.95

Z80A-P10 40 Parallel I/O Interface Controller 5.95

Z80A-S10/0 40 Serial I/O (TxCB and RxCB bonded) .16.95

Z80A-S10/1 40 Serial I/O (Lacks DTRB) 16.95

Z80A-S10/2 40 Serial I/O (Lacks SYNCB) 16.95

Z80A-S10/9 40 Serial I/O 16.95

Z80B 40 CPU (MK3880N-6) 6MHz 1 1 .95

Z80B-CTC 28 Counter Timer Circuit 13.95

Z80B-P10 40 Parallel I/O Interface Controller 13.95

Z8001 48 CPU Segmented 51.95

Z8002 40 CPU Non-Segmented 55.95

Z8030 40 Serial Comm. Controller 44.95

Z8036 40 Counter/Tlmer& Parallel I/O Unit... 29.95

6800/68000 SERIES

MC6800 40 MPU 4.95

MC6802CP 40 MPU with clock and RAM 7.95

MC6810API 24 1 28x8 Static RAM 3.95

MC6821 40 Peripheral Inter. Adapt (MC6820) 4.95

MC6828 24 Priority Interrupt Controller 15.95

MC6830L8 24 1024x8-blt ROM (MC68A30-8) 10.95

MC6850 24 Asynchronous Comm. Adapter 4.95

MC6852 24 Synchronous Serial Data Adapter .... 5. 75

MC6860 24 0-600bps Digital MODEM 9.95

MC6862 24 2400bps Modulator 12.95

MC8880A 16 Quad 3-state bus. trans. (MC8T26) . 2.25

MC68000L8 64 MPU 16-Blt (8MHz) 69.95

MC68488P 40 General Purpose Int. Adapter 8.95

MC68652P2 40 Multi. Protocol Comm. Controller. ,. .24.95

MC68861PB 28 Enhanced Prog. Comm. Int 8.95

SY6522 40 Peripheral Inter. Adapter 7.95

8080A SERIES

INS8080A 40 CPU 3.95

TMS5501 40 Synchronous Data Interface (SIRC) . . 14.95

INS8154 40 128 Byte RAM 16-Blt I/O 13.95

INS82C06 20 Octal 6 Flip Flop Tri-State (74C374) . . 2.49

DP8212 24 8-bit Input/Output (74S412) 2.25

DP8214 24 Priority Interrupt Control 3.95

DP8218 18 Bl-Olrectlonal Bus Driver 2.25

0P8224 16 Clock Generator/Drlver 2.25

0P8226 16 Bus Driver 2.25

DP8228 28 System Cont. /Bus Driver (74S428) . 3.49

0P8238 28 System Controller (74S438) 4.49

INS8243 24 I/O Expander tor 48 Series 5.95

INS8245 18 16-Key Keyboard Encoder (74C922) . .4.49

INS8246 20 20-Key Keyboard Encoder 74C923 . .4.95

INS8247 28 Display Controller (74C911) 8.95

INS8248 26 Display Controller (74C91 2) 8.95

INS8250N 40 Asyn. Comm. Element ...10.95

0P8251 28 Prog, Comm. I/O (USART) 4.49

0P8253 24 Prog. Interval Timer 8.95

DP8255 40 Prog. Peripheral I/O (PPI) 4.49

DP8257 40 Prog. DMA Control 7.95

OP8259 26 Prog. Interrupt Control 6.95

DP8275 40 Prog. CRT Controller 29.95

DP8279 40 Prog. Keyboard/Display Interface ... 8.95

0P8303 20 , 8-Bit Tri-State Bl-Olrectlonal Trans. .3.95

DP8304 20 8-bit Bi-Directional Receiver 2.49

DP8307 20 8-blt BI-DIrectlonal Receiver 2.49

DP8308 20 8-blt BI-DIrectional Receiver 2.49

0P8310 20 Octal Latched Peripheral Driver 4.95

0P831 1 20 Octal Latched Peripheral Driver 4.95

MICROPROCESSOR MANUALS & DATA BOOKS

M-Z80 User Manual 7.50

M-C0P1802 User Manual 7.50

M-2650 User Manual 5.00

30003 1982 Nat, Linear Book (1952 pg.) 11.95

30008 1980 Nat. Memory Data Book (464 pg. ) .6.95

30011 1980 Nat. Linear Applications (736 pg.) . .15.95

30013 1983 Zllog Data Book (641 pg.) 7.95

SPECIAL FUNCTION

DS0025CN 8 Dual MOS Clock Driver (5MZ) 2 .49

0S0026CN 8 Dual MOS Clock Driver (5MZ) 1.95

INS1771N-1 40 Floppy Disk Controller 16.95

INS2651N 28 Communication Chip 8.95

MM58167N 24 Microprocessor Real Time Clock 8.95

MM58174N 18 Micro. Compatible Time Clock 7.95

C0P402N 40 Microcontroller w/64-diglt RAM 5.95

and Direct LED Drive

COP402MN 40 Microprocessor w/64-diglt RAM 5.95

& Direct LED Drive w/N Buss Int.
C0P470N 20 32-seg. VAC Fluor. Drvr. (20-plnpkg.) 3.25

MM5369EST 8 Prog. Osclllator/Dlvlder (100Hz) . . . . 1 19

Part No.

-DYNAMIC RAMS-

1103

4027

4116N-2

4116N-3

4116N-4

4164N-150

4164N-200

MM5261

MM5262

MM5270

MM5280

MM5290-2

MM5290-3

MM5290-4

MM5298-3

1101

2101

2102

21L02

2111

2112

2114

2114L

2114-2

2114L-2

2141-3

2147

2148
TMS4044
TMS4045
5101
MM5257
HM6116P-3
HM6116-4
HM6116LP-4
7489
74C920
74C921
74C929
74C930
74S189
74S200
74S206
74S289
82S10
82S25

Price

16 4096x1 (250ns) 2.49

16 16.384x1 (150ns) 1.89 - 8/14.95

16 16.384x1 (200ns) 1.69-8/12.95

16 16,384x1 (250ns) 1 .49 - 8/10.95

16 65,536x1 (150ns) 7.95-8/59.95

16 65,536x1 (200ns) 7.49 - 8/54.95

18 1024x1 (300ns) 49-8/1.95

22 2046x1 (365ns) 49-8/1.95

18 4096x1 (250ns) MK4096 4.95

22 4096x1 (200ns) 2107 3.95

16 16,384x1 (150ns) 1 .89 - 8/14.95

16 16,384x1 (200ns) 1.69-8/12.95

16 16,384x1 (250ns) 1 .49 - 8/10.95

16 8192x1 (200ns) 169

STATIC RAMS

16 256x1 (650ns) 1.49

2.49

, 2.95

18 1024x4 (450ns) 1 95 - 8/13.95

(450ns) L.P 2.25-8/15.95

(200ns) 2.25-8/15.95

(200ns) L.P 2.49 - 8/17.95

(150ns) 3.95

70ns) 4.95

70ns) 8.95

450ns 3.95

(450ns CMOS 4.95

[450ns 4044 4.95

(150ns CMOS 7.95

[200ns CMOS 6.95

[200ns L.P. CMOS 7.95

50ns) 2.25

(250ns) CMOS (6551) 3.95

[250ns CMOS 3.95

250ns CMOS (6501) 3.95

250ns CMOS 6518 3.95

35ns) 93405 1.95

(80ns) 93410 3.95

80ns 93411 3.95

35ns 3101 2.25

50ns) O.C. (93415) 3.95

[50ns O.C. 74S289) 2.25

1702A

2708

2708-5

TMS2516

TMS2532

TMS2564

TMS2716

2718

2716-1

2732

2758Q

MM2764

MM2764-3

MCM88764

74S188

74S287

74S288

74S387

74S471

74S472

74S473

74S474

74S475

74S478

74S570

74S571

74S572

74S573

82S23

82S115

82S123

82S126

82S129

82S130

82S185

DM87S180N

DM87S181N

DM87S184N

0M87S185N

OM87S190N

OM87S 1 91 N

EPROM S —

“ lus) . .

24 256x8 ......

24 1024x8 450ns

24 1024x8 550ns

24 2048x8 450ns

24 4096x8 450ns

28 8192x8 450ns

24 2048x8 450ns

24 2048x8 350ns

24 4096x8

24 1024x8

2B 8192x8

28 8192x8

450ns

300ns

..4.91

SM00246 2.95

2718 6.95

NMC2532 9.95

24 8192x8 (450ns)..

.19.95

16 32x8
16 256x4
16 32x8
16 256x4
20 256x8
20 512x8
20 512x8
24 512x8
24 512x8

PROM O.C.
PROMTS.
PROMT.S.
PROM O.C.
PROMT.S.
PROMT.S.
PROM O.C.
PROMT.S.
PROM O.C.

8330- 1) 1,49

6301-1 1,95

8331- 1 1.95

8300-1 1.95

8309-1 5.95

6349-1) 4.95

DM87S296N) .4.95

24 1024x8 PROMT..
18 512x4 PROM O.C,
16 512x4

16 32x8
24 512x8
16 32x8
16 256x4
16 256x4
16 512x4

PROM O.C.
PROMT.S.
PROM T.S.
PROM O.C.
PROMT.S.
PROM O.C.

24 1024x8 PROMT...
18 2048x4 PROM O.C.
18 2048x4 PROMT.S.

DTI 050 — Applications: Teaching aids,
appliances, clocks, automotive, telecommunica-
tions, language translations, etc.

The DT1050 is a standard DIGITALKER kit encoded with 137 separate
and useful words, 2 tones, and 5 different silence durations. The
words and tones have been assigned discrete addresses, making it
possible to output single words or words concatenated into phrases
or even sentences. The “voice” output of the DT1050 is a highly in-
telligible male voice. Female and children's voices can be synthesiz-
ed. The vocabulary is chosen so that It is applicable to many pro-
ducts and markets.

The DT1050 consists of a Speech Professor Chip, MM54104 (40-pin)
and two (2) Speech ROMs MMS2164SSR1 and MM52164SSR2 (24-pin)
along with a Master Word list and a recommended schematic
diagram on the application sheet.

DTI 050 Digitaiker™ $34.95 ea.

DTI 057 — Expands the DT1050 vocabulary
from 137 to over 260 words. Incl. 2 ROMs and specs.
DTI 057 $24.95 ea.

•gf" ■l|l»KSfdl|Ll *m~

Part No. ••Pim Function Price

7045IPI 28 CMOS Precision Timer 14.95

7045EV/KH* 28 Stopwatch Chip, XTL 19.95

7106CPL 40 3% Digit A/D (LCD Drive) 9.95

FE0203D 3Vt Digit LCD Olsplay for 7106 & 71 16 19.95

7106EV/Kit* 40 1C, Circuit Board. Display 34.95

7107CPL 40 3V» Digit A/D (LED Drive) 11.95

7107EV/KU* 40 1C, Circuit doard, Display 29.95

7116CPL 40 3Yi Digit A/D LCD Dis. HLD 16 95

7117CPL 40 3V* Digit A/D LED Dis. HLD 15.95

7201 IUS Low Battery Volt Indicator 2.25

7205IPG 24 CMOS LED Stopwatch/Timer 12.95

7205EV/Klt* 24 Stopwatch Chip, XTL 14.95

7206CJPE 18 Tone Generator 4.95

7206CEV/KII* 16 Tone Generator Chip, XTL 7.95

7207AIPD 14 Oscillator Controller 5.95

7207AEV/KH* 14 Freq. Counter Chip. XTL 7.95

7208IPI 28 Seven Decade Counter 15.95

7209IPA 8 Clock Generator 3.95

7215IPG 24 4 Func. CMOS Stopwatch CKT 13.95

7215EV/KH* 24 4 Func. Stopwatch Chip, XTL 14 95

7216AIJI 28 8 Digit Unlv. Counter C. A 29.95

72L6CIJI 28 8 Digit Freq. Counter C. A 24.95

7216DIPI 28 8 Digit Freq. Counter C.C 19.95

7217IJI 26 4 Digit LED Up/Oown Counter C. A 10.95

7217AIPI 28 4 Digit LED Up/Oown Counter C.C 11.95

7224IPL 40 LCD 4’A Digit Up Counter DRi 10.95

7226AIJL 40 8 Digit Univ. Counter 29.95

7228AEV/KH* 40 5 Function Counter Chip, XTL 74.95

130009 1983 INTERSIL Data Book (i356p.) $9.951

jct ’ 74HC High Speed CMOS

TBP28S86) .8.95

8305) 2.95

8306) 2.95

8352) 4.95

82S137) 4.95

,2.95

DC10

MC3470P

MC1408L7

MC1408L8

ADC 0804

DAC0806

ADC0809

ADC 08 17

DAC1000

DAC1008

DAC1020

0AC1022

DAC1222

AF100-1CN

AF121-1CJ

AF122-1CJ

LM334Z

LM335Z

LM399H

AV-5-1013A

3.95
3.95

5.95

TBP24S81 ) . . .9.95

82S180) 9.95

82S181) 9.95

82S184 9.95

82S185) 9.95

82S190) . .19.95

62S191) . . 19.95

— DATA ACQUISITION

Mostek DC/DC Convert. +5V to -9V 2.95

18 Floppy Disk Read AMP System 4 95

16 7-blt D/A Converter (DAC0807LCN) 2.49

18 8-bit D/A Converter (DAC0808LCN) 2.95

20 8-bit A/D Converter (1 LSB) 3.49

18 8-blt 0/A Converter 0.78% Lin.) 1 .95

26 8-blt A/D Converter (8-Ch. Multi.) 4.49

40 8-blt A/D Converter (16-Ch. Multi ) 9.95

24 10-bit D/A Conv. Micro. Comp. (0.05%) 13.95
20 10-bit D/A Conv. Micro. Comp. (0.20%) 7.95

.75

74HC00 14

74HC02 14

74HC03 14

74HC04 14 ...

74HCU04 14 .75

74HC08 14 .75

74HC10 14 .75

74HC11 14 .69

74HC14 14 .85

74HC20 14 .75

74HC27 14 .75

74HC32 14 .75

74HC42 18 1.39

74HC73 14 .75

74HC74 14 .99

74HC75 18 .99

74HC76 16 .75

74HC85 16 2.19

74HC86 14 .99

74HC107 14 .75

74HC109 18 1.39

74HC112 16 .75

74HC113 14 .75

74HCU04 is unbuffered.

74HC132
74HC138
74HC139
74HC147
74HC151
74HC153
74HC157
74HC158
74HC160
74HC161
74HC164
74HC165
74HC173
74HC174
74HC175
74HC192
74HC193
74HC194
74HC195
74HC242
74HC243
74HC251
74HC253
l others are bi

74HC257 18 1.19

74HC259 18 1,49

74HC286 14 .99

74HC280 14 4.95

74HC373 20 3.95

74HC374 20 3.95

74HC390 16 1.49

74HC393 14 1.49

74HC533 20 3.95

74HC534 20 3.95

74HC595 3.75

74HC888 3.19

74HC4002 14 .79

74HC4020 16 2.19
74HC4024 14 1.59
74HC4040 16 2.19
74HC4060 18 2.19
74HC4075 14 .75

74HC4078 14 .69

74HC4511 16 3.29
74HC4514 24 4.79
74HC4538 18 2.95
74HC4543 16 4.95
Send 8.30 for Data Sheet.

16 10-bitO/AConv. (0.05% Lin.)

16 10-bit D/A Conv. (0.20% Lin.)

18 12-bft D/AConv. (0.20% Lin )

16 Universal Active Filter 2.5% s. 9 b

24 Touch Tone Low Band Filter 19.95

24 Touch Tone High Band Filter 19.95

Constant Current Source 119

Temperature Transducer 1 40

Temp. Comp. Prec. Rel. (,5ppm/C*) 5.00

40 30K Baud Uerl (TR1602) 4.95

Pert No. ♦•Pins Function

PAL10H8

PAL12H6

PAL14H4

PAL10L8

PAL12L6

PAL14L4

PAL16L8

1 3001 2

20 Octal 10-Input AND-OR Gate Array (High Output) . . .

20 Hex 12-Input AND-OR Gate Array (High Output)

20 Quad 14-Input AND-OR Gate Array (High Output) . .

20 Octal 10-Input AND-OR-Invert Gate Array (Low Output). .
20 Hex 12-Input AND-OR-Invert Gate Array (Low Output)

20 Quad 14-Input AND-OR-Invert Gate Array (Low Output) .
20 Octal 16-Input AND-OR-Invert Gate Array (Low Output)
20 Octal 1 6-Input Register AND-OR Gate Array
20 Hex 16-Input Register AND-OR Gate Array
20 Quad 16-lr ‘

■Input Register AND-OR Gate Array 9 95

1982 NATIONAL PAL Data Book(i 76 p.) . .$5.95]

QUALITY COMPONENTS AT
AFFORDABLE PRICES!

48HV

TTTTTTr

LOW PROFILE

(TIN) SOCKETS

1-9

10-99

100-up

8 pin LP

.16

.14

.13

14 pin LP

.17

.15

.14

16 pin LP

.19

.17

.16

18 pin LP

.26

.24

.23

20 pin LP

.30

.27

.25

22 pin LP

.31

.28

.26

24 pin LP

.33

.30

.28

28 pin LP

.40

.37

.35

36 pin LP

.46

.42

.39

40 pin LP

.49

.46

.43

SOLDERTAIL (GOLD)

STANDARD

1-9

10-99

100-up

8 pin SB

.30

.27

.25

14 pin SG

.43

.39

.37

16 pin SG

.47

.43

.41

18 pin SG

.63

.49

.47

24 pin SG

.69

.65

.61

28 pin SG

.81

.76

.72

36 pin SG

1.09

1.03

.97

40 pin SG

1.21

1.14

1.08

TrrmT

SOLDERTAIL

STANDARD (TIN)

1-9

10-99

100-up

14 pin ST

.29

.27

.25

■ 16 pin ST

.34

.32

.30

18 pin ST

.36

.34

20 pin ST

.45

.43

.41

24 pin ST

.49

.46

.43

28 pin ST

.69

.67

.63

40 pin ST

.99

.95

.89

WIRE WRAP SOCKETS

(GOLD) LEVEL #3

1-9

10-99

100-up

8 pin WW

.49

.45

.42

10 pin WW

.65

.62

.59

14 pin WW

.65

.62

.59

16 pin WW

.69

.65

.61

18 pin WW

.89

.85

.79

20 pin WW

1.09

1.05

.99

22 pin WW

1.25

1.19

1.15

24 pin WW

1.29

1.23

1.18

28 pin WW

1.59

1.50

1.45

36 pin WW

1.85

1.75

1.69

40 pin WW

1.99

1.89

1.79

California Residents Add 6Vz% Sales Tax
Shipping — Add 5% plus $1.50 Insurance
Send S.A.S.E. tor Monthly Sales Flyer!

Spec Sheets — 30c each

Send $1.00 Postage for your
FREE 1983 JAMECO CATALOG
Prices Subject to Change

Jarn^co

VISA

m m mm

1355 SHOREWAY ROAD, BELMONT, CA 94002
7/83 PHONE ORDERS WELCOME — (415) 592-8097 Telex: 176043

74C00

74C02

74C04

74C08

74C10

74C14

74C20

74C30

74C32

74C42

74C48

74C73

74C74

74C85

74C86

74C89

74C90

74C93

74C95

74C107

74C151

74C154

74C157

74C160

74C161

74C162

74C163

74C164

74C173

74C174

74C175

74C192

74C193

74C195

TL071CP 8
TL072CP 8
TL074CN 14
TL081CP 8
TL082CP 8
TL084CN 14
LM301CN 8
LM302H
LM304H
LM305H
LM307CN 8
LM308CN 8
LM309K
LM310CN 8
LM311CN 8
LM312H
LM317T
LM317K
LM318CN 8
LM319N 14
LM320K-5
LM320K-12
LM320K-15
LM320T-5
LM320T- 1 2
LM320T-15
LM323K
LM324N 14
LM337T
LM338K
LM339N 14
LM340K-5
LM340K-12

LM340K-15

1 30003 1982 Nat. Linear Data Book

74C221

74C240

74C244

74C373

74C374

74C901

74C903

74C906

74C911

74C912

74C915

74C917

74C922

74C923

74C925

74C926

80C95

80C97

.79

1.39

1.25

1.75

.69

2.49

1.19

3.95

1.95
1.95
1.35
1.35

5.95
.59

1.95

6.95
.69

1.35

LINEAR

LM340T-5
LM340T-12
LM340T-15
LM348N 1

LM350K
LF355N
LF356N
LM370N 1

LM373N 1

LM377N 1

LM380N 1,

LM381N 1

LM382N 1.

LM384N 1

LM366N-3 I

TL494CN II

TL496CP I

NE510A 1,

NE529A 1<

NE531V I

NE536H
NE540H
NE544N 1-

NE550A 1-

NE555V I

LM556N 1<

NE564N If

LM565N V

LM566CN (

LM567V (

NE570N If

LM703CN f

3.95

2.95

3.95

LM709N 14 .49

LM710N 14 .69

LM711N 14 .79

LM723N 14 .55

LM733N 14 1.00

LM739N 14 1.95
LM741CN 8 .35

LM747N 14 .69

LM748N 8 .59

LM1310N 14 1.49

LM1458CN 8 .59

LM1488N 14 69

LM1489N 14 .69

LM1496N 14 1.95

LM1800N 16 1.49

LM1889N 18 1.95

LM1896N 14 2.95

LM2002T 1.49

LM3189N 16 1.59

LM3900N 14 .59

LM3905CN 8 1.19
LM3909N 8 .99

LM3914N 18 3.49

LM3915N 18 3.49

LM3916N 18 3.49

RC4136N 14 1.25
RC4151NB 8 1.95
NE5532 8 2.49

NE5534 8 1.69

ICL8038B 14 3.95
LM13080N 8 1.19
LM13600N 16 1.19

MORE AVAILABLE

E AVAILABLE t

) .$11.95/

CIRCLE 20 ON FREE INFORMATION CARD

Wall Transformers
AC and DC Types

AC250 (Pictured)

Part No. Input Output Price

AC 250 (above) 117V/60Hz 12VAC 250mA $3.95

AC 500 117V/60HZ 12VAC 500mA $4.95

AC 1000 117V/60HZ 12VAC 1 amp $5.95

AC9004 117V/60HZ 9.2VAC2.5amp $3.95

DC 800 120V/60HZ 8VDC 400mA $1.95

DC6912 120V/60HZ 6,9,1 2VDC 300mA $8.95

DC5490 117V/60HZ 9.5VDC 275mA $2.95

DC900 120V/60HZ 9VDC 500mA $3.95

DC1200 120V/60HZ 9.5VDC 300mA $2.95

DV9200 117V/60HZ 9VDC 200mA $3.25

PCB-3

Makes Circuit
Assembly
A Breeze!

Lets you work
with both hands.
Sturdy aluminum
construction.

Clamp, "3rd Hand” on edge of bench table or workboard. Insert cir-
cuit board, position components. Notice convenient working angle.
Flip cifcult board to flat position for soldering and clipping. Reverse
procedure for double-sided boards.

PCB-3 $13.95

Mostek DC/DC Converter
+ 5 VOLTS TO -9 VOLTS

Input: +5V. Output: -9V (regulated) @ 30mA.
Printed circuit mounting. Specifications Incl.

DC10 $2.95ea.or2/S4.95

Digital Thermometer Kit

Dual sensors — switch
controls for Indoor/outdoor
or dual monitoring — can be
extended to 500 feet. Con-
tinuous LED .8* ht. display.
Range: -40‘F to 199*F, -40 *C
to 100 *C. Accuracy ±1*
nominal. Calibrate for
Fahrenhelt/CelalU8.
Simulated walnut case. AC
adapter Included. Size:

JE300. . . . . .$39.95

i'LxSH'Hk ly/D.

RADIO CONTROL CIRCUITS

Ideal to usa for

• Toys, hobby crafts, robots, trains

• Burglar alarms • IR data link

• Remote slide projector control

• Consumer remote data links

• Energy-saving, remotely switched lighting systems
A complete ^-channel digital encoder and RF transmitter; low power,
at frequency of 27MHz or 49MHz, a field strength of 10,000uV meter
at 3 meters. 9V operation on chip RF oscillator/transmitter, on chip
4.6 regulator. Up to 80MHz carrier frequency operation.

LM1871N RC Encoder/Transmitter Chip . . .$1.95

• Powerful - fully programmable 2K
memory • Portable - 6 7 / a " x 6%" x 1%" - 12
oz. • Expandable - Optional 16K RAM
module • Single-key entry commands

• Educational • Unique syntax-check report
codes for error identity • Accurate to 9V2
decimal places for full range math and
scientific functions • Graph drawing and
animated display • Advanced 4-chip design
combining power, portability and
affordable price.

TS1000 $69.95

ACCESSORIES FOR

lOOO and ZX81

HT7T3H -

gRF 10161 Expansion from 2K t. 16K, size: 3" x 3" x 1 .5" (5 oz) TS1016 S49.95

gil-nzlair- 2040 | 32 column thermal printer (4 lbs) TS2040 $99.95

A complete RF receiver/decoder, used at either 27MHz, 49MHz or
72MHz. It provides 4 Independent channels when used with LM1871
(2 analog, 2 dig.) operates from four 1.5V cells, Crystal controlled.

LM1872N RC Receiver/Decoder Chip $2.49

SRX1504 49.435MHz Crystal (LM1872N) . . .$3.95
SRX1505 49.890MHz Crystal (LM1871N) . . .$3.95

ATARI PADDLES

JSP (2) $4.95 pair

ATARI DRIVER

JSD(1) $2.95 ea.

TV GAME SWITCH

Used on Atari. Cosmet-
ically blemished. 100%
functional.

TGS-1 . . . $2.95 ea.

BOOKS

NATIONAL SEMICONDUCTOR - INTERSIL - INTEL

30003 National Linear Data Book (1982) $11.95

(1376 pages) LM, LF, ADC, DAC, LH Series

30008 National Memory Data Book (1980) $6.95

(464 pages) RAMs, ROMs, PROMs, EPROMs Series

30009 Intersil Data Book (1983) $9.95

(1356 pages) Complete line.

30010 National Audio/Radio Handbook (1980) $5.95

(240 pages) Pre-Amps, AM, FM & FM Stereo, Power Amps

30011 National Linear Application Handbook (1980) $15.95

(736 pages) Application Notes, Linear Briefs, etc.

3001 2 National PAL Data Book (1 982) $5.95

(176 pages) Application Notes, Linear Briefs, etc.

3001 3 Zilog Data Book (1 983) $7.95

(641 pages) Microprocessors and Support Chips

210830 Intel Memory Components Handbook (1983) $14.95

(798 pages) Contains all Application Notes, Article
Reprints, Data Sheets, and other design Information
on Intel’s RAMs, EPROMs, E’PROMs & Bubble Memories.
210844 Intel Microprocessor & Peripheral Handbook (1983) $14.95

(1027 pages) Contains Data Sheets on all of
Intel's Microprocessors and Peripherals.

Universal —^Computer Keyboard Enclosures

’’DTE” Blank Desk-Top Enclosures
are designed lor easy modifica-
tion . High strength epoxy molded
' end pieces in mocha brown finish .

Sliding rear/bottom panel for service/
component access’. Top/bott. panels .080"
, ^ thick alum, alodine type 1200 finish (gold tint

^ color) for best paint adhesion after modification.

Vented top & bottom panels for cooling efficiency.
Rigid construction provides unlimited applications.

Assembly instructions Included.

DTE-8 Panel Width 7.5 " $24.95

DTE-11 Panel Width 10.13" $27.95

DTE-14 Panel Width 13.5" $29.95

C DTE-20 Panel Width 19.25" $34.95

Keyboard Mask for Your
ZX81/1000* Computer

FEATURES:

adhatlva backing In
and placa ovar keyboard. ,

• All charactara and aymbola / i“5u

raproducad on maak. L < -~b ).

• Durable — formed with poly- f ~ ^

earbonlte ahaat ealln llnleh. JEStl KEYBOARD M,

The JE881 Keyboard Mask provides users of the
ZX81/1000 series computer the Individual feel of
each keypad on the keyboard. The mask has a rais-
ed outline around each keypad allowing the user to
feel and correctly position their fingers onto the
keyboard.

JE681 KEYBOARD MASK $9.95 each

ZX81/ 1000* Keyboard
Conversion Kit

JE6S2-AK KEYBOARD
KIT MOUNTED IN DTE-
AK ENCLOSURE. LIGHT
TAN PANELS WITH
MOLDED DARK BROWN
ENO PIECES. SIZE:
14'/.-W«3Vi-Oxjyi-H

The JE682 Kit provldea uaers ol Ibe ZXSinOOO i

dustrlal keyboard hook up to their computer, The JE882

either the full-size keyboerd or (he Slnclalr/Tlmex Keyboard. The mi aiao per-
mits Ihe simple disconnection ol Ihe Slnclalr/Tlmex Keyboard lor portable
use. The JE662 Kll constats ol a lull-size Industrial grade keyboard with 62
keys, 2 p.c. boards. 24* ribbon cable. DIP aockal and 4 rubber laal. The
keyboard convaralon kll can eaally be mounted Into the DTEAK enclosure
This enclosure Is large enough to contain the ZX81MOOO computer and the
lull-size keyboard together A handy label representing the ZxetMOOO

80- Key Keyboard

CA150C .

. .$69.95

84-Key Keyboard

CA153A $69.95

95-Key Keyboard

CA154A $79.95

CONTROL DATA KEYBOARDS

★ Parallel ASCII

★ SPST Switching

★ FTZ Shielded Base

★ N-Key Rollover

★ 128 Character ASCII

★ Non-Slip, Non-Glare Keycaps

★ COC752 Terminal Keyboards

★ Attractive Case

These Control Data Keyboards consist of a
base, cover, the keyboard assembly, and an in-
terface cable. Color (case): Harvest gold and
black. Color (keycaps): Black, blue, and red.
Electrical requirements: +5V @ 600mA, -12V
@ 50mA. Weight: 6 lbs. All units brand new In
original boxes, specifications included.

Keytronics 90- Key Soft-Programmable Keyboard >

WITH SECURITY KEYLOCK SWITCH

Made for Visual Technology, this keyboard features: a security keylock (includes two keys) to guard against
unauthorized use; an 11-key numeric keypad; cursor controls; and 10 user-programmable keys. Electrical re-
quirements: + 5VDC. Color (case); White. Color (keycaps): Black. Complete with case, keyboard assembly,
40-Inch Interface cable, and schematics. Weight: 7 lbs.

Part No. KB270 $109.95 each

RFI shielded brand

Cursor controls newii

Numtrlc keyboard
6-blt Parallel
Capacitance keys
10 utsr-programmabla keys
Positive TTL Logic
Size: 1 7 "L x 8Ve "W x 2V«*H

2708,2716,2732 & 2764 EPROM Programmer

JE664 EPROM PROGRAMMER

8K TO 64K EPROMS - 24 AND 28 PIN PACKAGES

— PROGRAMS 271 6’S IN 16 SECONDS —

• Programs, validates, and checks for properly erased EPROMs • Emulates PROMs
or EPROMs • RS232C Computer Interface for editing/program loading • Loads data
Into RAM by keyboard • Changes data in RAM by keyboard • Loads RAM from an
EPROM • Compares EPROMs tor content dltferences • Copies EPROMs • Power In-
put: 115VAC, 60Hz, ■* 10W power consumption • Enclosure: Color-coordinated,
light tan panels w/moldad mocha brown end pieces • Size: 15-5/8"L x 8 3 /.”D x
3'/z"H • Wt.: 5Ve lbs.

JE664-A EPROM Programmer $995.00

Assembled & Tested ( Includes JM16A Module)

JE665 - RS232C INTERFACE OPTION - The JE665 RS232C interface
Option implements computer access to the JE664's RAM. Sample software written in
BASIC provided for TRS-80® Model I, level II Compufer. Baud rate: 9600. Word
Lgth: 8 bits - odd parity. Stop bits: 2. Option may be adapted to other computers.

JE664-ARS EPROM Prog. W/JE665 Option $1195.00

Assembled and Tested (Includes JM16A Module)

EPROM JUMPER MODULES — The JE664 S JUMPER MODULE (Personali-
ty Module) Is a plug-in Module that pre-sets JE664 tor proper programming pulses to
the EPROM & configures EPROM socket connections tor that particular EPROM.

Part

No. EPROM EPROM MANUFACTURER PRICE

JM08A 2708 AMD, Motorola, National. Intel. Tl $14.95

JM16A 2716.TMS2516 Intel. Motorola, National, NEC. Tl $14.95

JM 16 B TMS2716 Motorola, Tl (+5,-12, +12) $14.95

JM32A TMS2532 Motorola. Tl $14.95

JM32B 2732 AMD. Fujitsu. NEC. Hitachi. Intel $14.95

JM32C 2732A(21V) Fujitsu, Intel $14.95

JM64A MCM68764,

MCM68L764 Motorola $14.95

JM64B 2784 Intel $14.95

JM64C TMS2504 Tl $14.95

JM64D HN482764G-4 Hitachi (21V) $14.95

EXPAND YOUR MEMORY

TRS-80 to 16K, 32K, or 48K

••Model 1 ■ From 4K to 16K Requires (1) One Kit

Model 3 - From 4K to 48K Requires (3) Three Kits

Color b From 4K to 16K Requires (1) One Kit

“Model 1 equipped with Expansion Board up to 4BK Two Klta Raqulrad
- Ona Kit Raqulrad lor aach 18K ol Expanalon -

TRS-16K3 *200ns for Color & Model III $12.95

TRS-16K4 *250ns for Model I $10.95

TRS-80 Color 32K or 64K Conversion Kit

Kit comes complete with 8 each 4164-2 (200ns) 64K dynamlo RAMa
and conversion documentation. Converts TRS-80 color computers
with D and E circuit boards, and all new color computers to 32K.
Minor modifications of 32K memory will allow the use of all 64K of
the dynamic RAM providing you have a FLEX DOS operating system.

TRS-64K2 $54.95

IBM MEMORY EXPANSION KIT

SAVE HUNDREDS OF $$$ BY UPGRADING
MEMORY BOARDS YOURSELF!

Most of the popular memory boards allow you to add an additional
64K, 128K, 192K, or 256K. The IBM64K Kit will populate thaas boards
in 64K byte Increments. The kit Is simple to Install — Just Insert the
nine 64K RAM chips In the provided sockets and sat the two groups
of switches. Directions are Included.

IBM64K (Nine 200ns 64K RAMs) $59.95

23”Lx5>/4 ,, Wx1-3/8”H

3*L x 3"W x 1 Vz "H

1"Lx4VWx iy/H

MICRO SWITCH 85-KEY KEYBOARD

Word Processing Keyboard, 28 Pin Edge Card Connection. Supply Voltage +5VDC. Main Keyboard
is QWERTY. Additional Kay Padi tor Curaor and word processing lunctlons.

Part No. 85SD18-1 $29.95 each

HI-TEK 14-KEY NUMERIC KEYPAD

SPST switching. Charcoal gray keycapa. Mounted on printed circuit board.

Part No. K-14 $9-95 each

ALPS 29-KEY CALCULATOR KEYBOARD

Features one 8-poaltlon decimal select switch, ono 3-posltlon switch, and two 2-poaltlon switches,
mechanical SPST switching, 22-pin edge card connection. Pln-out Included.

Part No. KB297040 (Fits DTE-11 Enclosure) $4.95 each

POWER SUPPLY + 5VDC @ 1 AMP REGULATED Transaction Tach

Output +5VDC @ 1A (also +30VDC) reg. Input 115VAC 60Hz. 2-tono (black/belge) self-enclosed
case. 6 ft., 3 cond. black power cord. 6Vz"W x 7"D x 2V«"H. Wt. 3 lbs. Data sheet Incl.

Part No. PS51194S $14.95each

POWER SUPPLY +5VDC @ 3 AMP REGULATED

Input: 115VAC, 47-440HZ. Output: 5VDC Adjustable @ 3 amp, 6VDC @ 2.5 amp. Adjustable cur-
rent limit, Ripple & Noise: 1MV rms, 5MV p-p - 2 mounting surfaces. UL recognized. Size: 4 W x
4 Vi”L x 2-7/16”H - wt. 2 lbs. Oata sheet Included.

Part No. QPS-1 $29.95 each

POWER SUPPLY +5VDC @ 7.5 AMP, 12VDC @ 1.5 AMP SWITCHING

Input: 115V AC, 50-60Hz @ 3 amp/230VAC. 50Hz ® 1.6 amp. Fan volt./power supply select swit-
ches (1 1 5/230VAC). Output: 5V0C @ 7.6 amp, 12V0C @ 1.8 amp. 8 ft. blk. pow. cord. 11Vz”W x
13'//0 x 3%"H. Wt. 6 lbs.

Part No. PS94V0S $39.95 each

POWER SUPPLY 4-Channel Switching - Apple Compatible

Microprocessor, mini-computer, terminal, medical equipment and process control applications. In-
put: 90-130VAC 47-440HZ. Output: +5V0C @> 5A, -5VDC ® 1A; +12VDC @ 1A, -12V0C @ 1A.
Line rea.: ±0.2%. Ripple: 30mV p-p. Load reg.: ±1%. Overcurrent protection. AdJ: 5V main oul-
put±10%. 6-3/8”L x 1-7/8"W x 4-15/16"H. Wt. 1 Vt lbs.

Part No. FCS-604A $69.95 each

$10.00 Minimum Order — U.S. Funds Only
California Residents Add 6y2% Sates Tax
Shipping — Add 5% plus $1.50 Insurance
Send S.A.S.E. for Monthly Sales Flyer!

Spec Sheets — 30c each
Send $1.00 Postage for your
FREE 1983 JAMECO CATALOG
Prices Subject to Change

Mail Order Electronics -Worldwide

ameco

ELECTRONICS

VISA 9

1355 SHOREWAY ROAD, BELMONT, CA 94002
7/83 PHONE ORDERS WELCOME — (415) 5 92-8097 Telex: 176043

5 Vi" Mini-Floppy Disk Drive

FOR TRS-80 MODEL I (Ind ‘ “

Features single or double d
-ode:FM-— -

. 12VDC ( ,

0.8A max. Unit as pic. at right (does not incl.
case, power supply, cables). 30-pg. data book
Incl. Wt. 3 Vi lbs. Size: 5 V* "W x (TD x 3 V. "H.

Part No. Limited Quantity I Price

FD200 $179.95

Single-sided, 40 tracks, 250K bytes capacity

FD250 $199.95

Double-sided, 35 tracks, 438K bytes capacity

8: FLOPPY DISK DRIVE

sis

• Shugart 801 R
compatible

• Single-Sided

• 77 Tracks

• 400/800K Bytes
Capacity

• Industry Standard

The FDD100-8 8" Floppy Disk Drive (Industry Standard) features
single or double density. Recording mode: FM single, MFM double
density. Transfer rate: 250K bits/sec. single density; 500K bits/sec.
double density. The FDD100-8 is designed to work with the single-
sided soft sectored IBM Diskette I, or eq. disk cartridge. Power:
115V AC @ 50-60Hz, +24VDC® 1.7 amps max., +5VDC® 1.2 amps
max. Unit as pictured above (does not include case, power supply, or
cables). Size; 8.55 "W x 14 "L x 4.5"H. Weighs 12 lbs. Incl. 96-pg.
manual.

Part No.

Price

FDD100-8 . .$1 69.95 ea.

UV-EPROM Eraser

8 Chips — 51 Minutes |

ife>

| 1 Chip — 37 Minutes

Erases 2708, 2716, 2732, 2764, 2516, 2532, 2564. Erases up to 8 chips
within 51 minutes (1 chip In 37 minutes). Maintains constant exposure
distance of one inch. Special conductive foam liner eliminates static
build-up. Built-in saiety lock to prevent UV exposure. Compact — only
9.00” x 3.70" x 2.60". Complete with holding tray tor 8 chips.

DE-4 UV-EPROM Eraser . . . . *79.95,

UVS-11EL Replacement Bulb . . ■ s 16.95 J

CIRCLE 20 ON FREE INFORMATION CARD

113

JULY 1983

FORMULA INTERNATIONAL INC

12603 Crenshaw Blvd., Dept. B. Hawthorne, CA 90250

For information (213) 973-1921 • Orders Only (outside Calif.) (800) 672-8758

pinecom"

The Alternative! The Compatible!
The Affordable! 64K Color Computer Kit!

FEATURES:

* Fully compatible with Apple® II +

* Singleboard for easy assembly

* Popular 6502 MPU for large
amount of software

yr w T w tAtn * Game paddle connector on both

sides of case

* Upper/lower case

Easy to assemble! All components are clearly silk-screened on the high quality double-sided mother board.
All integrated circuits, 1C sockets, peripheral connectors, keyboard, switching power supply and the pro-
fessional high impact plastic case are included. ’Pinecom is. a trade mark of Pineapple Computer Products (HK) Ltd.

(please add 5% shipping and handling)
DEALERS INQUIRIES INVITED!

* Built in 2-watt amplifier for realistic
sound effect with volume control

* 8 on board peripheral connectors
for expansion

* 14 key numeric key pad

* 5-amp switching power supply

* Auto repeat

SVa" DISC DRIVE FROM

100% Made in USA 100% Apple and Pincom Compatible
50% Faster Seeking Time Than Apple Disk II Drivel

• 1 Year Full Warranty

• 40 Tracks

• One of the Most Quiet Drives

• Color and Shape same as the
Disk II Drive

Disk Drive $285.00
C ontroller Card $ 75. OO
Controller Card with 13 Sector, 16 Sector Auto Select $ 85.00

The APPLE II LOOKALIKE COMPUTER CASE

Made with high impact plastic.

Color and shape are
compatible with K tfoe APPLE II

Keyboard not included with this price!

Model: API!

6502 CPU MOTHER BOARD

• 48 K on board RAM (4116)

• 1 2K on board ROM (2716)

• Upper/lower case

• Composite-video output

• Apple II alternative

• Size: UVV' x 8y 2 "

P.C. Board Only $99.00 ea.

Complete Component Pack (No ROMs) $175.00

GUARANTEED TO WORK! BUILD IT IN 2 HOURS!

• RR Big Savings On Peripheral Cards M M N

Buy them in kit form.

Ail cards APPLE II and PINEAPPLE compatible.

80 column card kit . . . $120.00

Z80 CP/M card kit $110.00

16K RAM card kit $49.50

RS232 Interface card kit $95.00

16K RAM card (cable-less) kit $59.50

EPROM writer card assembled
(For 2708,2716,2732,2764,2532) $89.50

Printer interface card kit (For Epson or Oki) $69.50
New disk controller card kit
(3.2, 3.3 auto select) $69.50

HEAVY DUTY SWITCHING POWER SUPPLY
for Apple II, AP-II™ and Pinecom Computers

-P5V at 5.0 Amp
-F12V at 2.5 Amp
-5V at 0.5 Amp
-12V at 0.5 Amp
Size and mounting holes are same
as the ones used in the Apple II

Model: THB-43H

$145.00 ea.

APPLE 11+ COMPATIBLE KEYBOARD

• LSI keyboard decoder

• Upper/lower case function

• Full ASCII code output

• N-key rollover function

• LED ON/OFF indicator

LKB-3600-N Keyboard Case

Keyboard Only $99.00 EA. Plastic Case $35.00 EA.

MICRO-II CASE

Made with ABS Plastic
Same size as the Apple II, with Numeric
Key-Pad and Upper/Lower Case.

$250.00 ea.

Keyboard Included

SEND ONE DOLLAR
FOR OUR DETAIL CATALOG

Inside California

Outside Calif, (incl. Mexico & Canada)
Overseas

Shipping & Handling Charges
Under S50.00 Under $50.00
Purchase Purchase

1 0% 5%

' 15 % . 10 %

25% 20%

Minimum Order SlO.OO/Calif . Residents
add 6.5% Sales Tax. Phone Orders Accepted
or. VISA or MC ONLY. NO C.O.D.s. Prices sub-
ject to change without notice.

STORE HOURS
MON-FRI— 10-7
SAT— 10-6

‘Apple and Apple II are the trademark of APPLE COMPUTERS, INC.

CIRCLE 76 ON FREE INFORMATION CARD

QUALITY

ACTIVE, YOUR
NUMBER ONE
CHOICE

SERVICE J

AVAILABILITY^

4c=nr=?

LctxvB:

LlIX.'J

Over $40 miflidn in stock. The world’s most
complete hopbyisjt-ihventory.

ActiVeEieCtronics is your one stop source for the

/ / / / // / / / [ [ ! I \ \ v x. \ \ \ v

Active Electronic^ is your one stop source toNhe '
widest variety of top quality- semiconductors,
microprocessors. i memories, microcomputer^
systenrs, peripherals and electronic components,

NEW — 1983 1C MASTER

The FIRST and ONLY
complete guide to IC’s,
Microcomputer Boards:
and Development
Systems.

Deluxe 2fVolume set
3300 pages
Regular Price:; $95.00

ACTIVE’S PRICE

ONLY $79.95

Call or write lot
\ e ur FREE \ ■ V -
comprehensive
catalogue. It you
work with
etectrdffrcs~you
shouldn’t be
without It!

Circle No. 3 on free Information card or write:
P.O. Box 8000, Westboro, Mass. 01581

CALL TOLL FREE: 1-800 343 0874

MASS, customers call (617) 366 0500

POPULAR CHIPS

LM 301

.39

LM 380

1.25

LM 386

.79

NE 564

2.50

LM 565

.89

MC 1330

1.10

MC 1350

1.00

MC 1358

1.10

MC 1458

.49

MC 1496

1.50

LM 1889

1.95

7808

.75

7812

.75

7815

.75

7818

.75

MV 2109

.69

2N2222A

.30

MC1349

1.39

CHOKES
.33 uh 33 uh

.47 uh 100 uh

15 uh 10 mh

18 uh 694 each

VARI CAPS

1 0 - 60 pf 694 each
30 - 90 pf 694 each

MITSUMI

UES A55F

VARACTOR TUNER

CHAN. 14-83

300 ohm INPUT $17.95

DELUXE PARTS ASSORTMENTS

#1 Resistor* A Trimpots

68 V4 watt, 5% resistors &
5 PT-15 10K trimpots. 1
each - 51, 75, 100, 470,
1.5K, 3.6K, 51 K, 470K.
13-1.2K, 2-220, 3-1 00K,
6-330, 6-1 2K, 7-910, 9-
3.3K, & 14-4. 7K.

$5.25 each
#2 Capacitor U A”
Monolythics - 1-560pf, 7-
.1 nifd, & 1-.22 mfd.
Silver Micas - 2-10pf, & 1
each of 43pf, 11 Opt,
560pf, 1200pf, 3000 or
3300pf.

$5.05 each
#3 Capacitor “B"

Mylars 4-.001, 2-.047, 29-
.01. Radial lytics 3-10
mfd 16V, 1-1000 mfd
50V, 1-2200 mfd 35V.
Disc Caps 1 each of 5,

12, 27, 36, 110, 330pf, 2-
120pf, 3-39pf, 3-220pf,
and 1 Vari Cap 5-35pT.

$7.50 each

#4 Coll A Chokes

1 each of 15, 33, and 100
(uh) micro henries
chokes. 1-variable RF
coil (same as
#49A537MPC)

$3.25 each

#5 IC’s, Sockets, A Sami’s
1 each of: NE564, LM565,
MCI 330, MCI 350,

MCI 496, LM1889, 7812,
7818, 2N2222A, MV2109,
heat sink 2-MC1458, 4-
1N4002, 4-8 pin, 2-14
pin, 1-16, & 1-18 pin
socket.

$13.25 each
#6 Misc. Hardware
LED & holder, fuse &
holder, line cord,
grommet, SPST switch,
DPDT switch, 2-F61
conn. & lugs, knob, 4-
spacers, 6-screws &
nuts, 2-RG-174, match-
ing transformer w/nut.
$5.95 each

UHF AMP KIT

25 db gain
stripline PC board
using

(2) BFR-90’s

$9.95

power supply
for above $3.49

METAL BOX-
PRE-DRILLED

DIM: 10*W x 4ViD x 3” High
HOLES: (4)3fe in back. (1)% in front
(2) %" in front, 6 #6 on bottom

PAINTED $10.95 ea . 10/S99.50
25/$223.75

CIRCUIT SPECIALISTS

74LS00 SALE

7400

74LS00

.20

74LS123

.50

74LS249

1.25

7400

.20

7475

.50

74LS01

.24

74LS125A

.50

74LS251

.60

7401

.29

7476

.38

74LS02

.24

74LS126A

.50

74LS253

.60

7402

.29

7485

1.10

74LS03

.24

74LS132

.80

74LS256

1.50

7403

.29

7486

.35

74LS05

.24

74LS133

.80

74LS257A

.60

7404

.31

7489

2.40

74LS08

.24

74LS136

.40

74LS258A

.60

7405

.32

7490

.52

74LS09

.24

74LS137

1.00

74LS259

1.25

7406

.38

7492

.52

74LS10

.24

74LS138

.80

74LS260

.55

7408

.31

7493

.52

74LS1 1

.24

74LS139

.80

74LS266

.55

7410

.30

7495

.67

74LS12

.24

74LS145

1.30

74LS273

1.25

7411

.31

7496

.73

74LS13

74LS147

1.65

74LS279

.55

7413

.46

74107

.35

.45

74LS148

1.65

74LS280

2.25

7414

.59

74121

.40

74LS14

.60

74LS151

.55

74LS283

.90

7417

.32

74123

.58

74LS15

.32

74LS153

.55

74LS290

.80

7420

.29

74125

.52

74LS20

.29

74LS155

.85

74LS293

.90

7425

.31

74145

.75

74LS21

.32

74LS156

.80

74LS295A

.95

7427

.32

74147

1.67

74LS22

.32

74LS157

.80

74LS298

.90

7430

.30

74151

.75

74LS26

.32

74LS158

.80

74LS299

2.60

7432

.31

74153

.75

74LS27

.32

74LS160A

.85

74LS322A 4.60

7437

.31

74154

1.17

74LS28

.32

74LS161

.85

74LS323

4.60

7438

.31

74157

.75

74LS30

.32

74LS162

.80

74LS348

1.75

7440

.29

74164

1.05

74LS32

.32

74LS163A

.80

74LS352

1.25

7441

1.00

74165

1.05

74LS33

.32

74LS164

.80

74LS353

1.25

7442

.60

74174

1.00

74LS37

.40

74LS165

1.25

74LS365A

.55

7446

.83

74175

.83

74LS40

.35

74LS166

1.25

74LS366A

.55

7447

.83

74176

.80

74LS42

.60

74LS168

1.25

74LS367A

.55

7448

.83

74177

.80 ■

74LS47

.89

74LS169

1.25

74LS368A

.55

7450

.29

74190

1.08

74LS48

1.00

74LS170

1.75

74LS373

1.35

7472

.35

74192

.99

74LS49

1.00

74LS173

.80

74LS374

1.25

7473

.35

74193

.99

74LS51

74LS54

74LS55

.29

74LS174

74LS175

74LS181

.55

.60

2.25

74LS375

74LS377

74LS378

.55

1.25

7474

.35

74196

.80

74LS73A

.42

74LS182

1.25

74LS379

1.25

74LS74A

74LS75

.42

.45

74LS183

74LS190

2.75

.85

74LS385

74LS386

3.50

.55

VOLT-

REGS

74LS76A

.45

74LS191

.85

74LS390

1.25

74LS77

.70

74LS192

.85

74LS393

1.25

7805

.80

LM317T

1.00

74LS78A

.49

74LS193

.85

74LS395

1.25

7806

.80

LM317K

3.75

74LS83A

.75

74LS194A

.80

74LS398

2.25

7808

.80

LM323K

6.95

74LS85

.90

74LS195A

.80

74LS399

1.25

7812

.80

LM350T

3.25

74LS86

.45

74LS196

1.00

74LS490

2.10

7815

.80

LM350K

5.50

74LS90

.45

74LS197

1.00

74LS540

2.10

7818

.80

LM338K

7.60

74LS91

1.10

74LS221

1.25

74LS541

2.10

7824

.80

LM337T

1.90

74LS92

.55

74LS240

1.25

74LS568

3.99

7905

1.30

78L05

.40

74LS93

.55

74LS241

1.25

74LS569

3.99

7906

1.30

78L12

.40

74LS95B

.65

74LS242

1.25

74LS620

2.00

7908

1.30

78L15

.40

74LS107A

.45

74LS243

1.25

74LS621

2.00

7912

1.30

79L05

.80

74LS109A

.45

74LS244

1.25

74LS622

2.00

7915

1.30

79L12

.80

74LS112A

.45

74LS245

1.75

74LS623

2.00

7918

1.30

79L15

.80

74LS113A

.45

74LS247

1.25

74LS640

2.00

7924

1.30

78H05KC

9.25

74LS114A

.60

74LS248

1.25

78H12KC

9.25

74LS122

.80

YOUR SEMICONDUCTOR
SUPERMARKET

LINEAR IC’S

LM301AN

.48

LM3900

.75

MC1489P

1.10

LM307N

.56

LM3909

1.00

MC1496P

1.48

LM308N

.71

LM391 1

1.50

MC1723P

.62

LM310N

2.40

LF347

2.35

MCI 741 CPI

.56

LM311N

.69

LF351

.60

MC3301

.90

LM318N

2.50

LF353

.99

MC3302

.80

LM319N

2.40

LF357

1.10

MC3401

.90

LM324N

.71

NE555

.42

MC3403P

1.30

LM325N

3.30

MC1306P

1.10

MC1648P

3.80

LM326N

3.30

MC1310

4.29

MC1658P

4.50

LM556N

.93

MC1330A1P

1.50

MC4024P

4.49

LM339N

.69

MC1349P

1.17

MC4044P

4.49

LM383T

2.30

MC1350P

.98

ICM7208

15.95

LM377N

2.40

MCI 351 P

1.70

ICM7207A

6.00

LM378N

3.15

MC1357P

1.49

ICM7217A

9.95

LM379N

4.60

MC1358P

1.30

ICM7205

12.95

LM380N

.90

MC1372P

4.42

ICM7045

15.50

LM381N

2.25

MC1373P

3.54

ICL8038

3.40

LM381AN

3.60

MC1403U

2.71

ICM7555

1.20

LM384N

2.00

MC1405L

9.70

MWA110

7.45

LM386N

.99

MC1413P

1.20

MWA120

7.80

LM565N

1.35

MC1374P

2.61

MWA130

8.25

LM566N

2.30

MC1376P

2.08

MW A3 10

8.25

LM567N

1.35

MC1458CP1

.77

MWA320

8.65

LM1889

3.20

MC1488P

1.10

ZN414

2.00

CMOS

CD4001

.30

CD4046

1.50

MCI 4000

.40

MCI 4023

1.22

. ' *

CD4007

.32

CD4047

1.40

MCI 4001

.40

MCI 4024

1.06

CD4010

.55

CD4049

.45

MCI 4002

.40

MCI 4024

.40

CD4011

.32

CD4050

.45

MCI 4006

1.42

MCI 4027

.72

CD4013

.45

CD4051

1.00

MCI 4007

.40

MCI 4028

1.02

xxli

CD4016

.50

CD4066

.65

MCI 4008

1.25

MCI 4032

1.93

CD4017

1.00

CD4069

.32

MC14012

.40

MCI 4034

3.50

CD4020

1.17

CD4070

.45

MCI 401 3

.72

MCI 4035

1.86

CD4023

.32

CD4071

.32

MCI 401 4

1.25

MCI 4038

2.19

CD4024

.83

CD4081

.32

MC14015

1.47

MCI 4040

1.47

CD4025

.32

CD4093

.60

MCI 401 6

.72

MCI 4042

1.06

Y :

CD4027

.55

CD4510

1.17

MC14017

1.25

MCI 4043

.99

CD4029

1.42

CD4511

1.20

MCI 401 8

1.15

MCI 4044

.99

CD4040

1.17

CD4515

2.80

MCI 4020

1.47

MCI 4046

1.57

CD4044 .80

MOST MOTOROL

CD4518 1.17

A CMOS IN STOCK

MCI 4021

1.25

MCI 4049

.72

: :

CIRCUIT SPECIALISTS INC.

BOX 3047, SCOTTSDALE, AZ 85257
(602) 966-0764

INCLUDE $1.25 SHIPPING

CIRCLE 44 ON FREE INFORMATION CARD

CIRCLE 3 ON FREE INFORMATION CARD

NETWORK SALES, INC.
2343 W. BELMONT AVE.
CHICAGO, IL. 60618
312-248-3202

TERMS: Visa, M.C., Check,
Money Order or COD (add
3.00). Min. Order $10.00. Add
$2.50 SAH for USA III. add 7 %
Tax. MAIL ORDER ONLY.
Phone Orders Welcome.
WRITE FOR OUR MONTHLY
UN-ADVERTISED SPECIALS

CIRCLE 90 ON FREE INFORMATION CARD

JULY 1983

With purchase of COMPLETE SET OF PARTS & ENCLOSURE

rexcell
ave Co

“The Deluxe II”

Is The Ultimate In UHF Sine Wave
Converter Technology

PC BOARD & PLANS $20.00

printed circuit
r kit that outper-

The latest state jflfc flfflrt electronics combi
manufacturing creates this high performance UHF
forms the imitations by a long shq}. -

Engineered for reliable stability aitdoutstandjng reception clarity, uninterrupted modulated
audio and fully illustrated inq|gftloi^with thefypiateur in mind.

TOLL FREE

^222, LAS VEGAS, NEVADA, 89109 1 “800 “ 782-2701

BETA ELECTRONICS, 1700 E. DESERT INN ROA!

QTY

DESCRIPTION OF ITEM

COST

EACH

SHIPPING

EACH

TOTAL

PC BOARD, PLANS, PARTS & ENCLOSURE

$152.99

$4.95

PARTS & ENCLOSURE ONLY

$132.99

$4.95

PC BOARD & PLANS ONLY

$30.00

$1.50

GRAND

NAME TOTAL

PLEASE

PRINT CLEARLY

SEND THIS
ORDER FORM

ADDRESS

QUANTITY DISCOUNTS AVAILABLE

CITY/STATE/ZIP ORDER DATE

MO. DAY YR.

□ VISA □ MST. CARD CARD NO. EXP. DATE

— ■ FOR IMMEDIATE DELIVERY MONEY ORDERS OR CERTIFIED CHECKS PREFERRED — PERSONAL CHECKS ALLOW 4 WEEKS FOR DELIVERY —

CIRCLE 67 ON FREE INFORMATION CARD

DoKq

VISIT OUR RETAIL STORE

Computer
Products,
ST0RE Inc.

1702

2708

2716

2716-1

2532

2732

2764

EPROMS

Ins

450ns

350ns

450ns

DYNAMIC RAMS

TMS 4027 250ns

3250 KELLER STREET, #9

8000

UPD 411

MM 5280

MK4108

MM 5298

4027

4116

4164

8035

4.95

8251

4.39

8039

5.95

8253

6.89

8080A

3.89

8253-5

7.89

8085A

5.89

8255

4.39

8086

24.95

8255-5

5.19

8088

34.95

8257

7.89

8155

7.75

8259

6.85

8156

8.75

8272

39.00

8185

- 29.00

8275

29.00

8202

27.95

8279

8.89

8205

3.45

8279-5

9.89

8212

1.79

8282

6.49

8214

3.75

8283

6.49

8216

1.69

8284

5.49

8224

2.19

8286

6.49

8226

1.79

8287

6.49

8228

3.34

8288

24.95

8237

19.00

8289

39.00

8238

4.39

8741

34.95

8243

4.39

8748

14.95

8250

10.49

8755

29.95

SANTA CLARA, CA 95050

16K APPLE
RAM CARD

Upgrade your 48K Apple II to
full 64K

BARE BOARD 14.00

ASSEMBLED & TESTED 42.50

300ns

200ns

250ns

200ns

150ns

200ns

150ns

2.95

2.98

3.25

4.69

4.15

CALL

.79

2.89

1.74

2.00

CALL

STATIC RAMS

2101

450ns

1.80

2102L-2

250nsLP

1.44

2111

450ns

2.48

2114

450ns

1.74

2114L-4

450nsLP

1.84

2114L-3

300nsLP

1.84

2114L-2

200nsLP

1.94

TMS4044-4

450ns

3.15

TMS4044-3

300ns

3.45

TMS4044-2

200ns

3.89

MK4118

250ns

9.69

TMM2016

200ns

4.15

TMM2016

150ns

4.89

HM6116-4

200ns

CALL

HM6116-3

150ns

CALL

HM6116-2

120ns

CALL

Z6132

300ns

32.95

= LOW POWER

EPROM ERASERS

HOLDS 15 EPROMS
ERASES IN 20 MINUTES

59.95

CONNECTORS

RS232 Male 3.00
RS232 Female 3.50
RS232 Female RA 4.95
RS232 Hood 1.20

74LS00 SERIES

74LS00

.23

74LS123

.49

74LS253

.58

74LS01

.23

74LS124

1.24

74LS257

.58

74LS02

.23

74LS125

.44

74LS258

.58

74LS03

.23

74LS126

.44

74LS259

1.19

74LS04

.23

74LS132

.54

74LS260

.58

74LS05

.23

74LS136

.54

74LS266

.58

74LS08

.23

74LS137

.89

74LS273

1.48

74LS10

.23

74 LSI 38

.49

74LS275

3.20

74LS11

.25

74 LSI 39

.49

74LS279

.48

74LS12

.25

74LS145

1.19

74LS280

1.79

74LS13

.39

74LS147

2.39

74LS283

.68

74LS14

.39

74LS148

1.29

74LS290

.74

74LS15

.29

74LS151

.39

74LS293

.78

74LS20

.23

74LS153

.39

74LS295

.98

74LS21

.23

74LS154

1.89

74LS298

.88

74LS22

.23

74LS155

.59

74LS324

1.74

74LS26

.29

74LS156

.69

74LS352

1.28

74LS27

.23

74LS157

.44

74LS353

1.28

74LS28

.29

74LS158

.49

74LS363

1.34

74LS30

.23

74LS160

.68

74LS364

1.89

74LS32

.25

74LS161

.64

74LS365

.48

74LS33

.49

74LS162

.68

74LS366

.48

74LS37

.29

74LS163

.64

74LS367

.44

74LS38

.29

74LS164

.68

74LS368

.44

74LS40

.23

74LS165

.79

74LS373

.98

74LS42

.43

74LS166

1.69

74LS374

.98

74LS47

.49

74LS168

1.69

74LS377

1.24

74LS48

.74

74LS169

1.74

74LS378

1.15

74LS49

.74

74LS170

1.45

74LS379

1.34

74LS51

.23

74LS173

.68

74LS385

1.89

74LS54

.23

74LS174

.44

74LS386

.44

74LS55

.28

74 LSI 75

.39

74LS390

1.15

74LS63

1.19

74LS181

1.89

74LS393

1.15

74LS73

.34

74LS189

8.79

74LS395

1.15

74LS74

.34

74LS190

.79

74LS399

1.48

74LS75

.34

74LS191

.79

74LS424

.37

74LS76

.34

74LS192

.64

74LS447

.37

74LS78

.45

74LS193

.64

74LS490

1.94

74LS83

.59

74LS194

.68

74LS668

1.69

74LS85

.65

74LS195

.68

74LS669

1.89

74LS86

.35

74LS196

.78

74LS670

1.48

74LS90

.35

74LS197

.78

74LS674

9.45

74LS91

.79

74LS221

.74

74LS682

2.99

74LS92

.54

74LS240

.89

74LS683

2.99

74LS93

.54

74LS251

.89

74LS684

2.99

74LS95

.74

74LS242

.98

74LS685

2.99

74LS96

.69

74LS243

.98

74LS688

2.39

74LS107

.35

74LS244

.79

74LS689

2.99

74LS109

.35

74LS245

1.48

74LS112

.35

74LS247

.74

81LS95

1.48

74LS113

.35

74LS248

.89

81LS96

1.48

74LS114

.35

74LS249

.89

81LS97

1.48

74LS122

.39

74LS251

.58

81LS98

1.48

Z80

4.0 MHz

Z80A-CPU 4.90

Z80A-PIO 4.90

Z80A-CTC 4.90

Call for Complete List

MICROPROCESSOR
REAL-TIME CLOCK

WE WILL BEAT
ANY COMPETITOR'S
PRICES!

Call before you buy

MSM5832

6.90

CRYSTALS

6500

UPGRADE

32.768 KHz
1.00 Hz

1.8432

1.90

4.50

6.144

6.5536

8.0

2.69

1 MHz

YOUR

2.0

3.90

10.0

2.69

6502

5.25

2.097152

3.90

12.0

2.69

6504

6.85

APPLE

2.4576

2.69

14.31818

2.69

6505

7.60

3.2768

2.69

15.0

2.69

6507

9.85

3.579545

2.69

16.0

2.69

6520

3.95

TRS-80

4.0

2.69

17.430

2.69

6522

4.95

5.0

2.69

18.0

2.69

6532

6545

5.95

16.95

4116 200ns

5.0688

5.185

2.69

18.432

20.0

2.69

6551

10.95

8/10.00

5.7143

6.0

2.69

22.1184

2.69

DISC
CONTROLLERS

1771

15.95

1791

27.95

1793

29.95

1795

49.95

1797

49.95

6843

32.95

8272

39.00

UPD765

34.95

1691

17.95

INTERFACE

8T26

1.65

8T28

1.95

8T95

.95

8T96

.95

8T97

.95

8T98

.95

DM8131

2.90

DP8304

2.25

DS8835

1.89

DS8836

.99

1C SOCKETS

W/W

8 PIN .10

.49

14 PIN .12

.50

16 PIN .15

.57

18 PIN .20

.85

20 PIN .25

.99

22 PIN .25

1.30

24 PIN .25

1.40

28 PIN .35

1.50

40 PIN .40

1.80

ST = Soldertail

W/W = Wirewrap

ORDER TOLL FREE

(800) 538-8800
(800) 848-8008

(CALIFORNIA RESIDENTS)

ALL MERCHANDISE IS 100% GUARANTEED

APPLE

SUPER COOLING
FANS

49.95

WITH SURG PROTECH

69.95

LINEAR

LM301

.32

LM741

.29

LM308

.75

LM747

.75

LM309K

1.25

LM748

.49

LM311

.64

LM1310

2.45

M317T

1.65

MC1330

1.69

LM317K

1.70

MC1350

1.25

LM318

1.49

MC1358

1.69

LM323K

3.75

LM1414

1.49

LM324

.59

LM1458

.55

LM337K

3.90

LM1488

.65

LM339

.79

LM1489

.65

LM377

2.25

LM1800

2.45

LM380

1.25

LM1889

2.45

LM386

1.00

LM3900

.59

LM555

.38

LM3909

.95

LM556

.65

LM3914

3.70

LM565

.95

LM3915

3.70

LM566

1.45

LM3916

3.70

LM567

.99

75451

.35

LM723

.49

75452

.35

LM733

.95

75453

.35

DoKqu

APPLE

PADDLES

9.95

’ rviAu Computer Products, Inc.
^^3250 Keller Street, #9
Santa Clara, CA 95050
(800) 538-8800

Calif. Residents (800) 848-8008

STORE HOURS:
MON-FRI 8:30 A.M.-5:30 P.M.
SAT 10:00 A.M.-3:00 P.M.

BankAmericard

[master charge]

APPLE* II

COMPATIBLE
DISK DRIVE

225.95

CONTROLLER CARD
79.95

TERMS: For shipping include $2.00 for UPS

Ground. $3.00 for UPS Blue Label Air. $10.00
minimum order. Bay Area residents add 6%% Sales
Tax. California residents add 6% Sales Tax. We
reserve the right to limit quantities and substitute
manufacturer. Prices subject to change without
notice. Send SASE for complete list.

CIRCLE 99 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

CHANEY

electronics inc.

Minimum Order S9.00
Please include $1.50 lor
shipping (UPS)

• We accept VISA and
MASTERCHARGE

• EXTRA FAST SERVICE

P,0. BOX 27038, DENVER. COLO. 80227
PHONE ORDERS: 303-781-5750

120V AC VARIABLE STROBE UGHT KIT

Complete variable rate strobe light kit produces bril-
liant flashes of light. Operates from standard
1 20VAC . Reliable design —thousands of these are „

in use throughout the world. Overall size of com-
pleted board: 3"L x 2"W x 3"H.

C3071 S9.99

3VDC ELECTRONIC WARNING FLASHER KIT

This portable battery operated device continuously
emits bursts of intense light at a fixed repetition
rate. Can be seen for great distances making it a
great safety device. Features xenon flashtube. Operates
on 3V0C (two 1.5V Batteries). Size of board: 2V2"L x :
C3207 $7.95

FASCINATION STAR KIT

Produces an “exploding star” visual effect using 25
LEDS and 1C circuitry. The center LED lights first then
the next group of LEDS light and then another set of
lights until the outer edge of the star lights up. The
process then reverses itself. Operates from 9V bat-
tery. C4432 $10.95

SEQUENTIAL LED FLASHER KIT

This kit combines 1C circuitry and 10 jumbo red
LEDS to produce a unique visual display. LEDS
continuously light sequentially from right to left. Easy to
build kit. Operates from 9V battery. Size of board: 5.25" x 1.5".

C4431 $6.75

MICRO-MINIATURE

SPEAKER

Only Vie” dia.
mounted on a
1" square PC
board.

C4832 $1.49

ea.

SOLID CARBIDE \
PC DRILL BIT 1

#65 .035

Standard size for
PC boards. |

C4800 $1.49 ea.

10 for $12.00

KESTER PC TYPE SOLDER

6 foot coil of ultra thin diameter
low melting temperature
60/40 rosin core.

C4456

$1.00

FINEST QUALITY

Government Approved QQ-S-571e

SOLDER

ill We oiler over 70 complete electronic kits.
IV 1X3 ! ! ! Send lor our tree catalog

CIRCLE 34 ON FREE INFORMATION CARD

SPECIAL
FOR THE MONTH

Good until June 30, 1983

SN 60/40 Rosin Core (RA)

One lb. Reels

16 swg. (.064) $8.50

18 swg. (.048) $8.95

19 swg. (.040) $9.50

21 swg. (.032) $10.50

% lb. Reels

22 swg. (.028) $6.95
24 swg. (.022) $8.95

PliicFRFF Desoldering Wick

■ lUu I IILL with each pound of solder

FREE Freight On All Orders Over $25

Under $25 add $2.50 per order. Minimum order $10
■ Check ■ Money Order ■ Master Charge ■ Visa
Jtp N.Y. State residents add appropriate sales tax.

#To place your order call:
/ T0LLFREE800-645-4808

In NYS (516) 334-2660 No COD'S accepted

CIRCLE 69 ON FREE INFORMATION CARD

Gray mark Electronic Kits

Quality Products for 18 Years

Digital Dice

Roll-’em electronically. Handy, portable set of
electronic dice for your favorite games. 14
LEDs for realistic dice count, Battery operated.
PCB, instructions, and all parts included.

Order Model 1 46F Only $15.90 each

♦in-

variable Strobe Light

Great for parties and photography.
Variable flash rate of long life xenon
tube assures hours of fun. AC operat-
ed. Comes complete with parts, PCB,
and instructions.

Order Model 1 04F Only $14. 70 each

Warbling Siren

Two-tone oscillating siren for auto-
mobile or other 12V system. Loud,
penetrating sound driven by 2 ICs.
Parts, PCB, and instructions are all
included.

Order Model 124F

Only $8.60 each

5 Volt Power Supply

Perfect for digital circuits. Provides
1.5 amps at 5V under full load. 1C
voltage regulator. Ripple less than
0.5%. AC operated. Includes all ne-
cessary parts, PCB, and instructions.

Order Model 1 35F Only $18.20 each

1-IC Radio

H Private earphone listening to your
favorite stations. AM broadcast band
with high selectivity. No alignment
necessary. Battery operated. Comes
complete with parts, PCB, and
instructions.

Order Model 1 41 F Only $12.00 each

MC & VISA orders only call Toll Free

800-854-7393

CA residents add sales tax • We pay shipping on orders
over $25.00, otherwise add $2.50. Sorry no COD.

(In CA 714-540-5480)

Send $1.00 for Catalog [over 60 Kits]

(Refundable with 1st Order)

Box 17359 • Irvine, CA 92713

SATISFACTION GUARANTEED

FUJITECH AUDIO KITS

LATEST AUDIO TECHNOLOGY
FROM JAPAN

Model A 501 Power Amp

* Pure Class A 25W + 25W

* Switchable to Class AB 100W + 100W

* Switchable to Bridge Class A 100W mono

* Switchable to Bridge Class AB 300W mono

* Frequency Response 5-200KHz (-IdB)

* Signal-to-Noise Ratio 120dB

* Non-magnetic Chassis

* “Out-board” comprehensive protection
circuitry

* DC circuitry with limited use of NFB

* High Efficiency Fluid Convection Cooling

* THD under 0.007%

KIT ONLY
$299.00

$299.00

Model A502 DC Stereo Control Center

* Direct DC coupling from Input to Output

* DC servo circuitry

* Cascade FET Input In all stages

* Separate Moving Coil RIAA amplifier

* Distortion below 0.005% (3V)

* Max Output 15V

* Frequency Response 20Hz-20KHz ±0.2 dB

* Maximum Phono Input

MC = 16mv RMS (IKHz)

MM = 270mv RMS (IKHz)

* Built-in Headphone amplifier

* Relay Output Muting KloAnT

$349.00

Model A1033 Integrated Tube Amplifier

* Latest Japanese Design

* Distortionless Output Transformer using
special winding techniques

* Most circuitry on PCB for easy assembly
and humfree performance

* Output 30W x 2 Ultra Linear

(Switchable to Triode)

15W x 2 Triode Output
(near class A performance)

* THD under 0.4%

* Frequency Response 30 '-30,000 Hz (-IdB)

* Separate Pre-Out and Main-In

H, ts. (• <*» - r

jm—A - , .£*? , i .

K- ' "’L

$499.00

Send $5.00 for each assembly manual,
refundable with order.

Monarchy Engineering, Inc.

380 Swift Avenue, Unit 21
South San Francisco, CA 94080
Visa or Mastercharge acceptable.

118

(602)971-0990 (602)971 0996

SURPLUS ^1$,

^ Wholesale - Retail - Surplus O
Electronic Parts

12627 N. Cave Creek Rd. • Phoenix, AZ 85022
The Most Unbelievable Electrolytic Sale In The USA!

AXIAL RADIAL

33/6.3

12/1.00

1000/10

12/1.00

220/6.3

20/1.00*

•

10/16

30/1.00*

470/6.3

10/1.00

47/16

30/1.00*

220/10

15/1.00

-1

220/16

25/1.00*

47/35

12/1.00

470/16

20/1.00*

220/35

10/1.00

47/25

20/1.00*

15/50

20/1.00*

47/100

5/1.00

22/50

20/1.00*

100/100

4/1.00

47/50

20/1.00*

4.7/160

10/1.00

1 50/50

8/1.00

10/160

10/1.00

220/50

8/1.00

22/250

5/1.00

10/75

12/1.00

BIPOLAR

47/100

5/1.00*

4/50

10/1.00

1500/100

2/1.00*

<#>

10/50

10/1.00

2.2/150

12/1.00

•

4.7/75

4/1.00

3.3/150

12/1.00

10/75

4/1.00

47/200

5/1.00

Carbide Drill Bits *1 .00 ea.
(various sizes to %")

• Yes All Prices Are Correct! • $10.00 Minimum Order on
All Above Capacitors • Some Quantity Pricing Available •

MORE SI .OO SPECIALS

1N4001

15/M .00

Horz P C. Trimpots, 250Q,

2N3905

5/*1 .00

500Q, 5kO, 10Q

4/M

2SC828

5/*1 .00

MC3420P

MOO

2SC644

5/M .00

SN75150

MOO

MINI D.P.D.T. Slide 4/M

Transformer

MOO

D.P.D.T. Rocker Sw

12 V.C.T. 250 MA

4A. 1 20 VAC

3/M .00

7805

2/M .00

1N4152

25/M .00

7812

2/M .00

Similar to 1 N914

1N5239

20/M .00

4 Pos DIP switch

i 3/M .00

9 V. ZENER

LED's

8/M .00

w/Transformer & 4" x 2.3" Heat Sink

$5.50 ea. or 2/S10.00

IV 2 WATT
AMPLIFIER

w/DC Bridge

*2 7S ea. or 2/*5

Contains: Volume Control, (1) LM 386N, (1) NPN
Pre-amp, (4) 4001 Diodes, (2) Coupling Caps
100% Functional! NOT A KIT

LIMITED QUANTITY!

s 3 29 ea. or 2/ s 6

4 Scales

(1) R.F. Power 0-6

(2) SWR 1-10

(3) Modulation 0-100%

(4) Signal Strength 1 -40
Ext. Shunt 2.3" x 2.3"

ITEMS MC, VISA, COD VIA UPS
(Plus Shipping/Handling) \

MICROWAVE

TRANSISTORS

420 ea.

M 2369

■ f T 4.5 GHz

■ NF 1.5 dB @ 1GHz U

■ MAG 14 dB @ 1GHz

■ V cbo 25V

■ Replaces NE021-37, MFR-901

420 ea. in lots of 1,000 (larger quan-
tity pricing is available)

1SS98 MIXER DIODE

■ Glass Package (type DO-35)

■ V F =0.34 V Max @ 1mA

■ Replaces MBD-101

154 ea. in lots of 1,000 (larger quan-
tity pricing is available)

Just call Jeff or Linda TOLL
FREE at 1-800-543-4330 or
1-800-762-4315 (in Ohio).

licit

ELECTRONICS

CONVERTERS

DESCRAMBLERS

Largest Selection
of Equipment Available

$ Buy Warehouse Direct & Save $

36 channel
converter

$4595

36 channel
wired remote
converter

only

$ 88 95

Send $2 for complete catalog
of converters and unscramblers

Quantity Discounts • Visa • Master Charge
Add 5*^0 shipping— Mich, residents add 4°7o sales tax

C&D Electronics, Inc.

P.O. Box 21, Jettison, MI 49428

CIRCLE 35 ON FREE INFORMATION CARD

(616) 669-2440

ORDER NOW

TOLL FREE

800-854-4655

OUTSIDE CALIFORNIA

714-635-5090

INSIDE CALIFORNIA

R.F. ELECTRONICS

i 1056 N. STATE COLLEGE BLVD., DEPT. R Q

ANAHEIM, CALIFORNIA 92806

PERSONAL CHECKS HELD FOR CLEARANCE - NO MINIMUM ORDER
ALL PREPAID ORDERS 2 LBS OR LESS MUST INCLUDE $2.50 SHIPPING & HANDLING — SHIPPED SAME DAY RECEIVED

CIRCLE 89 ON FREE INFORMATION CARD

CIRCLE 27 ON FREE INFORMATION CARD

119

JULY 1983

RADIO-ELECTRONICS

120

“THE NEW DELUXE II”

The new leader in sinewave technology
is now available at industry shattering
prices. We also have the new and
improved plusewave kit.

New Deluxe II Board with free-com-
plete assembly plans 20.00

New Deluxe II complete kit and en-
closure 119.95

Pulse Wave AD- 1 board with free com-
plete assembly plans 20.00

Pulse Wave AD-1 complete kit and

enclosure 119.95

Add 5% shipping and handling for Con-
tinental U.S. Add 10% shipping and
handling for outside Continental U.S.

GAMMA ELECTRONICS

455 Massachusetts Avenue

Arlington, Mass. 02174

To Order Call:

1-617-641-0778

COD

DEALERS WANTED

CIRCLE 21 ON FREE INFORMATION CARD

c,fteA^ Take^ Sale!

Take

12” CRT MONITOR
2 for 1 Special

Untested 12" CRT
Monitors, no broken tubes,
all are whole, but untested.
12” P-31 phosphor, transformer
AC, 120/220 VAC Includes schematic

Buy 1 Get 1 FREE S 39°L

Add $5 Packaging Plus Shipping

THIS MONTH
ONLY

• RS32 ASCII Input • Fully Formed Type • Up to 1200
Baud (120 cps) for almost 60 Ipm • 120 Columns at
10 pitch • Changeable Print Band • Ultra Reliable •
94 Characters (Upper & Lower Case) • 115 VAC 60
Hz • MFG’R's PRICE OVER $5K

One unit is fully tested and operational, cleaned and
ready to use. The other is clean and whole but UN-
TESTED (use as a spare or as parts machine). Line
Cord & Forms Tractor NOT included (available from
GE direct!) Tractor GE Part No. 44C414730-G02.

2 FORI . SOQCOO

SALE PRICE Only LUUPair

(Add $30 for Pkg.-Pay Shpg. on Delivery)

Take &

MPI/CDC 9404

• Single sided single density

• Removed from equipment
to install DSDD drives

• Includes data & schematics

• Untested, complete

Plus Shipping 2/SI 99 00

“SELECTRIC” 745
I/O Printers

• No time to test ’em

• Complete w/TTL
driver inputs

• IBM model 745 I/O printer

• Use as a typewriter
or printer

Cleaned & Adjusted
Fully Operational

Plus Shipping ($20. 00 Ea. Pkg.)

JUST

$279™
*399

100

We Stock New “Selectric” Parts
For The Above

Write or Call Now

For Our NEW BARGAIN-PACKED FLYER

C omputer
products &
■ ireripherals

Pnlimited

WAREHOUSE: 18 Granite St.. Haverhill. Mass. 01830
MAIL ORDERS: Box 204, Newton, New Hampshire 03858

617/372-8637

mSS^ Sorry No Collect Calls

MasterCard & VISA Accepted ' — '

CIRCLE 68 ON FREE INFORMATION CARD

Components is Out First NomCl/Call Us with Your Requirements

Easy on the Eyes. Connects to most
popular computers 04 % mm nn

w/o interface or $D CUU

modifications Ow

SW'Floppy

DISKETTES

All Certified-1 00% Guaranteed

BOX of100...*149°°

H b ub V Rings. $169.00

COEX 80-FT d p°rTnte™ x

• 9x7 Dot Matrix, 80 CPS, ^

Bi-Directional Printing /

• 2K Buffered Memory \

• 80, 96, 132 Columns, j v j

Graphics and Block Printing / ™ J

• Selectable Char Pitch, Line 1

APPLE lie 64K RAM CARD

80 x 24, 64K RAM

Compatible with *4 jinOO

Apple lie Software 143

FLOPPY DISK DRIVE

Apple lie Compatible
with • Track Zero Micro Switch
• DOS 3.2.1 & DOS 3.3

Spacing and Feed

COEX Interface Card to Apple . . $49.95 ■■ AH

Commodore Interface Card to V 3 M

VIC, 64, PET $79.95 f

for APPLE

16 K RAM CARD

Language Transparent
COEX FACTORY $ Ca g 5
WARRANTY

• CP/M and PASCAL

DESIGNED

FOR YOUR $09 C00

APPLE” faJJ

VISION-80® $00000

80x24 Video Display Card w

Vista Computer Company’s new Vision-80 board is a sophisticated
yet easy to use video display card for the Apple™ computer.

Controller Card M _ __

for above $75.00

EXTENDER CARDS

for APPLE... $16.95
for I.B.M $19.95

A COMMODORE?

NEW ROM for COEX 80 & DP8480

Allows Full Graphics Compatibility

with All Commodore Computers *29 s

PARALLEL INTERFACE

EPSON TO APPLE

$AQ95 CABLE

INCLUDED

New From

COEX

“Have You Kissed Your Computer Lately”

Components Express, Inc.

1380 E. Edinger • Santa Ana, Calif. 92705 • 714/558-3972
TWX 910-595-1565 • ADVACON SNA • International Orders Welcome
Terms of Sale: Cash, Checks, Credit Cards, M.O., C.O.D. FOB Santa Ana. Calif, residents add 6% sales tax.

VISA*

CIRCLE 88 ON FREE INFORMATION CARD

ramsa^j the first name in Counters !

9 DIGITS 600 MHz $129^ IRPn

WIRED

SPECIFICATIONS:

PRICES

CT-90 wired. I year warranty
CT-90 Kit. 90 day parts war-
ranty

AC- 1 AC adapter
BP-1 Nicad pack +AC
Adapter/Charger
OV-I, Micro-power Oven
time base

External time base input

The CT-90 is the most versatile, feature packed counter available for less
than $300.00! Advanced design features include; three selectable gate times,
nine digits, gate indicator and a unique display hold function which holds the
displayed count after the input signal is removed! Also, a lOmHz TCXO time
base is used which enables easy zero beat calibration checks against WWV.
Optionally, an internal nicad battery pack, external time base input and Micro-
power high stability crystal oven time base are available. The CT-90,
performance you can count on!

Range:

Sensitivity.

Resolution:

Display
Time base:

20 Hz to 600 MHz
Less than 10 MV to 150 MHz
Less than 50 MV to 500 MHz
0.1 Hz (10 MHz range)

1.0 Hz (60 MHz range)

10.0 Hz (600 MHz range)

9 digits 0.4” LED

Standard- 10.000 mHz, 1.0 ppm 20-40° C.
Optional Micro- power oveirO.l ppm 20-40°C
8-15 VAC @ 250 ma

7 DIGITS 525 MHz $99f IRED

SPECIFICATIONS:

Range:

Sensitivity

Resolution:

Display:
Time base:
Power

20 Hz to 525 MHz

Less than 50 MV to 150 MHz

Less than 150 MV to 500 MHz

1.0 Hz (5 MHz range)

10.0 Hz (50 MHz range)

100.0 Hz (500 MHz range)

7 digits 0.4" LED

1.0 ppm TCXO 20-40° C
12 VAC @ 250 ma

The CT-70 breaks the price barrier on lab quality frequency counters.
Deluxe features such as; three frequency ranges - each with pre- amplification,
dual selectable gate times, and gate activity indication make measurements a
snap. The wide frequency range enables you to accurately measure signals
from audio thru UHF with 1 .0 ppm accuracy - that’s .0001%! The CT-70 is
the answer to all your measurement needs, in the field, lab or ham shack.

PRICES:

CT-70 wired, 1 year warranty

$99.95

CT-70 Kit, 90 day parts war-

ranty

84.95

AC-1 AC adapter

3.95

BP-1 Nicad pack + AC

adapter/ charger

12.95

7 DIGITS 500 MHz $ 19 ^

WIRED

PRICES:

MINI- 100 wired, 1 year

warranty

$79.95

AC-Z Ac adapter for MINI-

100

3.95

BP-Z Nicad pack and AC

adapter/ charger

12.95

Here’s a handy, general purpose counter that provides most counter
functions at an unbelievable price. The MINI- 100 doesn’t have the full
frequency range or input impedance qualities found in higher price units, but
for basic RF signal measurements, it can’t be beat! Accurate measurements
can be made from 1 MHz all the way up to 5 00 MHz with excellent sensitivity
throughout the range, and the two gate times let you select the resolution
desired. Add the nicad pack option and the MINI- 100 makes an ideal addition
to your tool box for "in- the- field” frequency checks and repairs.

SPECIFICATIONS:

Range:

Sensitivity

Resolution:

Display
Time base:
Power

1 MHz to 500 MHz
Less than 25 MV
100 Hz (slow gate)

1.0 KHz (fast gate)

7 digits, 0.4” LED

2.0 ppm 20-40° C
5 VDC @ 200 ma

8 DIGITS 600

MHz $159^

WIRED

SPECIFICATIONS:

Range: 20 Hz to 600 MHz

Sensitivity Less than 25 mv to 150 MHz
Less than 1 50 mv to 600 MHz
Resolution: 1.0 Hz (60 MHz range)

10.0 Hz (600 MHz range)
Display. 8 digits 0.4” LED

Time base: 2.0 ppm 20-40° C
Power 110 VAC or 12 VDC

The CT-50 is a versatile lab bench counter that will measure up to600 MHz
with 8 digit precision. And, one of its best features is the Receive Frequency
Adapter, which turns the CT-50 into a digital readout for any receiver. The
adapter is easily programmed for any receiver and a simple connection to the
receiver* s VFO is all that is required for use. Adding the receiver adapter in no
way limits the operation of the CT-50, the adapter can be conveniently
switched on or off. The CT-50, a counter that can work double- duty!

PRICES:

CT-50 wired, 1 year warranty
CT-50 Kit, 90 day parts
warranty

RA- 1 , receiver adapter kit
RA-1 wired and pre- program-
med (send copy of receiver
schematic)

$159.95

119.95

14.95

29.95

DIGITAL MULTIMETER $99 ^ IRED

PRICES:

DM-700 wired, 1 year warranty

$99.95

DM-700 Kit, 90 day parts

warranty

79.95

AC-1, AC adaptor

3.95

BP-3, Nicad pack +AC

adapter/ charger

19.95

MP-1, Probe kit

2.95

The DM-700 offers professional quality performance at a hobbyist price.
Features include; 26 different ranges and 5 functions, all arranged in a
convenient, easy to use format. Measurements are displayed on a large 3'/i
digit, ‘/i inch LED readout with automatic decimal placement, automatic
polarity, overrange indication and overload protection up to 1 250 volts on all
ranges, making it virtually goof-proofl The DM-700 looks great, a handsome,
jet black, rugged ABS case with convenient retractable tilt bail makes it an
ideal addition to any shop.

SPECIFICATIONS:

DC/ AC volts: lOOuV to 1 KV, 5 ranges
DC/ AC

0.1 uA to 2.0 Amps, 5 ranges
0. 1 ohms to 20 Megohms, 6 ranges

Current

Resistance:

Input

impedance:

Accuracy.

Power.

10 Megohms, DC/ AC volts
0.1% basic DC volts
4 'C' cells

AUDIO SCALER

For high resolution audio measurements, multiplies
UP in frequency.

• Great for PL tones

• Multiplies by 10 or 100

• 0.01 Hz resolution!

$29.95 Kit $39.95 Wired

ACCESSORIES

Telescopic whip antenna- BNC plug $ 7.95

High impedance probe, light loading 15.95

Low pass probe, for audio measurements 15.95

Direct probe, general purpose usage 1 2.95

Tilt bail, for CT 70, 90, MINI- 100 3.95

Color burst calibration unit, calibrates counter
against color TV signal 14.95

COUNTER PREAMP

For measuring extremely weak signals from 10 to 1,000
MHz. Small size, powered by plug transformer-included.

Flat 25 db gain
BNC Connectors

Great for sniffing RF with pick-up loop
$34.95 Kit $44.95 Wired

ramssij ;h :iii li :v in.

2575 BAIRD RD. • PENFIELD, NY 14526

PHONE ORDERS
CALL 716-586-3950

IT. RMS Satisfaction guaranteed - examine for 10 days, if not pleased,
return in original form for refund Add 5% for shipping
insurance to a maximum of $ 1 0. Overseas add 1 5%, COD, add
$2. Orders under S 1 0., add SJ .50. NY residents, add 7% fax.

121

CIRCLE 79 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

□IBI-KEY

CORPORATION

-346-5 1 44

In Mn„ Ak.. Hi. Call 218-681-6674

aUALI ll - "‘ me ^ md f r ¥ a ‘ ts [ ram recognised manufacture.

OK MACHiNf ^ • mo L . E rr rHPM?r aFq F . i SERVICE - Computerized order processing and inventory control, as instruments • itt • a> products VDia I
NA^SS Volume Discounts . OEM Quantity Pricing • Toll Free BOO I

suHix-^Dfollow^^he^rt numbed Afte^writ^ng Z?SSr ’ toTol 'all ^ ? T C K° mb ' ned '° r 0 volu ™ discou "’ thof ■" no. d.scountable are identified by the

,hC “none! 96 ' ^ PQy a " Sh,PPm9 ° nd inSUfQnCe ,0 ° ddresses 10 ,he U-S. A. . Canada^nd Me^co^when pa r y 0 ment e accomponies 0 order U ' 3 ' 0,al add Ihe nen-disceun.ab'e .terns. Then add

items" Then add SERVICE CHARGES VOLUME DISCOUNT

WMfu nunmiur >, \ uuuresses in me u.i a Lanado and Mexico when payment accompanies order. s O-OO-S 9.99

Too may pay by check money order Master ^ '* ^ ^ »» *"» * IsIoSl^SS

replaced or refunded if returned within 90 days from receipt with a copy of your invoke^ ^ produC,S purchosed from wtg;-.,ey thot prove to be defective will be 5 50.00-S99.99

Add $ 2.00 S 0.00 $ 99.99 NET

. Add $0.75 $ 100.00-S249.99 ... Less 10%
Add $0.50 $ 250.00-S499.99 Less 15%

. Add $0.25 $ 500.00-S999.99 Less 20%

$100.00 & Up No Charge $1000.00 & Up Less 25“

122

CIRCLE 39 ON FREE INFORMATION CARD

□161-KEY

CORPORATION

- 346 - 5 1 44

n Mn., Ak.. Hi. Call 218 681-6674

Th ff° wn « V n ° SC0U * ond hon ^' n 9 char 9 es are simple to apply. Most items sold by Digi-Key may be combined for o volume discount. Items that ore not discountable ore identified by the H ANDI INC fHADAFC VOLUME ni^mi IMT
suffix-ND following the part number After writing your order, total all of the discountable items and apply the appropriate discount To this subtotal, odd the non-discountoble items Thenodd nMr4UL,l>1 '^ V-hAKutb VULUArtt UlbLUUNI

the handling charge. We pay all shipping and insurance to addresses in the U S A.. Canada and Mexico when check or money order accompanies order ? ° °° s 999 Add s20 ° S O.OO-S 99.99 NET

WHEN ORDERING BY PHONE. CAU: 1 800 346.5144 (Mn., Ak., Hi., call 2 1 8 681 -6674, By mail s.ndyaur ard.r ,o: OIGI-RET, Highway 32 South, Thi.f River Fall,. MN 56701 | lo.lo $ ! ! ! [ll\ ]vl

You may poy by check, money order Master Chorge ViSAorC.O.D DIGI-KEY GUARANTEE: Any ports or products purchased from Digi-Key thot prove to be defective will be 5 50.00-S99.99 Add $0.25 $ 500.00-S999.99 . . . .Less 20%

^replaced or refunded if returned within 90 days from receipt with a copy of your invoice. Prices subject to change without notice. $100.00 & Up No Charge $1000.00 & Up Less 25°- ■

CIRCLE 39 ON FREE INFORMATION CARO

123

JULY 1983

RADIO-ELECTRONICS

MORE GAIN

Than a Varactor UHF Tuner

PROFESSIONAL

TECHNICIANS & SERVICEMEN

WE CAN SUPPLY ALL THE COMPONENTS FOR YOUR
MAINTENANCE, REPAIR & DESIGN WORK

REPLACEMENT FOR ECG®TYPES (Min. 5 pcs. each type)

TYPE

YOUR

TYPE

YOUR

TYPE

YOUR

NO.

PRICE

NO.

PRICE

NO.

PRICE

... .30

152

... .40

375. . . .

1 23A . . .

... .25

153....

... .40

500A . .

. . . . 8.95

124

... .95

154....

... .65

523....

. 10.20

128

165....

...2.25

526A. . .

. 10.75

129

238. ,, .

...2.25

712....

.1.25

130

291....

... .99

852....

. . . . 4.95

SUPER SPECIAL (Min. 5 pc. each)

TYPE NO. YOUR PRICE

276 6.95 EXACT REPLACMENT FOR SG613H

2SC1172B 100 PCS. FOR 1.60 EACH

SPECIAL JAPANESE TYPES (Min. 5 pcs. each)

2SC867A 2.75 AN214Q 1.45 UPC1181H . . . 1 .25

2SC1172B... 1.95 M51515BI 2.95 UPC1 182 . . . . 1 .25

2SC1308K. . . 1 .95 TA7205AP ... 1.25 STK435 3.95

FOR ACOMPLETE 1983 COMPONENT CATALOG CALLOR WRITE

CALL TOLL FREE 800 - 526-4928
IN NEW JERSEY (201) 379*9016

COD ORDERS WELCOME ($25 Min. Order)

DIGITROIS ELECTRONIC

110 Hillside Avenue, Springfield, N.J. 07081

*ECG IS A TRADE MARK OF PHILIPS ECG.

DIGITRON ELECTRONIC IS NOT ASSOCIATED IN ANY WAY WITH PHILIPS ECG.

124 CIRCLE 84 ON FREE INFORMATION CARD

Out-of-state orders over $15 call Toll Free 1-800-251-5555
Tennessee residents and information requests call 1-615-244-4444

CIRCLE 29 ON FREE INFORMATION CARD

GILCO ORDER FORM

#B20 GILCO Hy-Gain Modified Tuner $ 15 00 _

#B21 GILCO Predrilled, Screen Printed, Circuit Board $ 17 00 _

#B22 GILCO Parts Kit (Less P/C Board) $ 80 00

#B20, B21 , B22 Complete P/C Board and Parts Kit (all three) . . $ 110 00

#A02 Two stage, 28 db gain, Amplifier Kit $ 18 50 _

#A03 One stage, 14db gain, Amplifier Kit $ 10 50 _

Name Total

Address Tax

City State Zip Ship

Mail Order Only. Send check or money order to: Total _

GILCO INTERNATIONAL, INC.

P.O. Box 8817, Coral Gables, Florida 33124
CALL (305) 823-5891 for COD orders PLEASE WRITE FOR OUR FREE CATALOG
Shipping Orders under $50 add 10%, Orders over $50 add 5%, FL residents +5% Tax

Bargains 1 1 1
ACAC-1 or ACPP-1

JAVAN CO

YOUR PARTS SUPERMARKET

160 2nd Ave.S.,
Nashville, TN 37201

s 15 00 SATISFACTION GUARANTEED

Frequency Range 470-899 MHz Channels
14-83. Output Channel 3. Ch 2 or 4 Avail.

PART #B20 $ 15°°

WHAT’S IN IT?

To make a regular UHF tuner into a GILCO HIGH GAIN TUNER, each and every one of
the following steps is painstakingly taken by a certified technician:

1. The first thing GILCO does is change the standard diode to a hot carrier diode.

2. The tuner’s output is then measured on our JERROLD field strength meter and com-
pared to a computer derived chart from which we determine the correct value coil to add
across the IF output for maximum pre-peaked gain.

3. The tuner is then fed a standard 1 0db 300 ohm antenna input and while monitoring the
output on our HEWLETT PACKARD spectrum analyzer, the tuner is tuned to the desired
channel and its oscillator is offset for the desired output frequency as follows:

Channel 2: 58 Mhz, Channel 3: 63 Mhz, Channel 4: 68 Hhz
We call this step peaking because the tuner’s output looks like a peak on our spectrum
analyzer and the highest point of that peak is actually adjusted for the desired output.

4. The last step is one more measurement on the field strength meter which is again com-
pared to our performance chart to calculate the correct value of the second coil which is
added to the tuners internal connections.

This procedure was developed by GILCO and it is our computer derived performance
charts that make our tuner better, that’s because almost every tuner gets a different value
coil before it’s peaked and again a different value coil after it’s peaked. The combinations
are endless and the way we determine the values is our secret...

10 ft. audio extension
cable. $ 1 .50

PCS.

PER .

KIT

7 0 ECKA-72 Mini-axial Kit
/ ^ ^ ,$6.85

UVE1-A Mitsumi
UHF/VHF combo
varactor tuner $9.75

ECKR-72 Mini-lytic Kit
$6.85

Calculator
keyboard switch
$9 9R

SPK

-100 PIEZO TWEETER $6.75 each
or $4.65 with $15 order!

This quality hi-fi horn is easily installed
without crossover.

ECK-251 $9.35 assorted miniature elec-
trolytics, all good useable values, in a
plastic bag. 251 PCS

1000 long lead resistors, % and % watt
assortment $ 6.75

GILCO PARTS KIT &
PRINTED CIRCUIT BOARD

• Use with GILCO
High Gain Tuner

• Requires NO Modification to
Your Television

• Individually Packaged and
Labeled Parts Save
Guesswork

The only tools required for
assembly are: screwdriver, solder-
ing iron, voltmeter. No drilling is re-
quired to the P/C board. Pre-drilled, pre-screened, plated through the

• This kit was designed to take ad- holes P/C board. All hardware, connectors, 22

vantage of the GILCO high gain tuner P a 9 a illustrated instruction manual, & Gilco Hy-

which means its circuitry is simpler ®a//i tuner. Kit assembles in just 4 hours,

and more efficient than those circuits that require inferior varactor tuners.

FREE 22 Page Instruction Book included with each P/C Board or Parts Kit. This in-
struction book will guide the builder through every step of the assembly. Nearly every
page is illustrated. With this Instruction Book, estimated assembly time is 4 hours

HERE’S WHAT YOU GET FROM GILCO
Part No. B21 Printed Circuit Board

$1700

resist. This prevents solder bridges.

4. Newest Addition: the P/C board is plated
through the holes. This allows for easier
and more positive soldered contact between
the parts and the P/C board.

s 80°°

1 . This Printed Circuit Board uses only one
jumper, others use nine.

2. The component layout is screen printed
on the component side of the P/C board.

3. The solder side of the P/C board is
covered with high temperature solder
Part No. B22 Complete Electronic Parts Kit
All resistors (30), Potentiometers (1-5K, 3-10K), Panel Mount Potentiometer (10K), Elec-
trolytic Capacitors (6), Ceramic and Mylar Disc Capacitors (35), Variable Capacitors (4),
All Integrated Circuits (7), Voltage Regulator, Heat Sink, Diodes (4), 1C Sockets (4-8 pin
3-14 pin), Power Transformer (24V, 1 A), Coil Kit with No. 26 wire (4), Speaker (4”.
3oz.), Standoffs, Coaxial Cable, All Miscellaneous Harware, Etc. All parts are individually
packaged and labeled.

All components including the Wire, Hardware, Coaxial Cable and Heat Sinks are includ-
ed in the parts kit. This means your assembly time from start to finish is just 4 hours

GILCO ACCESSORIES & AMPLIFIER KITS

#A02 New 2 stage, low noise, 28db gain, RF Amplifier Kit.
#A03 New 1 stage, low noise, 14db gain, RF Amplifier Kit.

$1 8 o°

$ 10 50

LADmiNCED
r COMPUTER
[PRODUCTS

16K Apple™ Ramcard

LIST 195
ACP

$ 59 95

• Full 1 year warranty
• Top quality — gold fingers
Expand Apple II 48K to 64K
• Compatible with Z-80 Softcarcf

NOW AVAILABLE

Apple lie 64K Add-in Memory * .

with 80 Columns 5 I 49 95

32K STATIC RAM

2 or 4 MHz

1 Expandable
Uses

21 14L’s

16K 4 MHz Kit $159.95

1 6K 4 MHz A&T Q _ 217.95

32K 4 MHz Kit 51 29 95 '289 ! «6.

• 32K 4 MHz A&T • 339.00

BARE BOARD 39.95

Bare Bdw/all parts less mem. 99.95

64K CMOS

^RAMCARD

IEEE

Uses

- ow Power
6116 IC’s

$00000 5Vo,t

Single Supply

■■ ^0 Assm and Tested

REPEAT OF SELL-OUT

58 Key Unencoded Keyboard

M‘19«..

This is a new 58 key terminal Keyboard
manufactured by a major manufacturer,
it is uncoded with SPST keys unat-
tached to any PC board. Solid molded
plastic 1 1" x4" base.

Unencoded —

Key

15 key Keypad with

1-10 keys and tab,

0„>T ’9”..

INTEL 4 W C

Super Fast!

SjPTOH Super

Low Power!

Part No. 2147 $1 .95 ea.

STEPPER MOTOR

Operates by applying
12VDC in one direc-
t * on anc * then revers ‘
W ^ ;) ing polarity (or square

• ,~ : 7 wave). Uses 12VDC,

Clock Wise Rotation,
.1. Rated 3 RPM at 4

TOL P.P.S. with a 5 degree
PRICE stepping angle.

$Q95

Oea. 10 for $34.95

UV “EPROM”

ERASER

Model

$89.95

Holds 4 EPROM'S
at a time.

Model S-52T $325.00

RS232 SIGNAL TESTER

COEX RS232
.TKh Line Tester

T«||m2Q1 ' (71 LED Indicators

only *Z4

Other Styles Also Available

16K Memory
Expansion Kits

for Apple/TRS-80

8 pcs 41 16 16K

200/250nS <£-< Q Qr

Specify computer 1

CALL FOR VOLUME PRICING

INTEL CODEC 1C

P/N 291 OA

For Digital

Voice

*9 95 ..

For Filter P/N 291 2A ... $4.95 ea.

CORCOM FILTER

J/k Popular

MM.. CORCOM
* Filter

Compatible Line Cord Add ... $3.50

SURGE

\~S SUPPRESSOR

I “Surgeonics”

Power Sentry

j 15 Amps 260 Volts
w A transient suppression

*39”

Astec RF Modulator
for

COLOR

!. • rt &

b/w

P/N 1082 Channel 3 or 4 $6.95

CONNECTORS

DB25P (RS232) $3.25 1

AMD MODEM 1C

AM7910

1 200Baud

5 Volts

Special ACP Prlce*99°°

DB25S Female 3.75

Hood 1,25'

Set with Hood, Sale 7,50

22/44 S/T, KIM 2,95

43/86 S/T, MOT 6.50

50/100 S- 100 Connector W/W 4.95

50/1 00 S- 1 00 Connector S/T 3.95

1 PARALLEL ALPHA NUMERIC

BB PRINTER

19 Column Printer prints 16 numerical columns plus 3

I columns which have math, alpha and other notations.

Position 1 1 on numerical columns have decimal point or #. Utilizes 2.75"
wide adding machine tape and a dual color Ink ribbon. Input data parallel
withfourbitBCDcomparatorcircult(schematic provided). Print rate, 3 lines
per second. Operating voltage 22-28VDC with typical cycle time of
340 mS. Size 6Vs"W x 3WH x 5%"Dp. New. $8.95 ea. 3/$25

6551
Z80-PIO
Z80A-PIO
Z80-CTC
Z80A-CTC
Z80-DMA
Z80A-DMA 27.95
Z80-SIO 24.95
Z80A-SIO 29.95

MOS PROMS

2764 (8Kx8) TS
2732 (4Kx8) TS
2716/2516; 5V
(2Kx8) TS
TMS2716, 5V, 12V
2758, 5V, (450nS)

7.95

17.95

3.50

2708 (450nS) $5.75
2708 (650nS) 5.25
1702A 5.75

MM5203AQ 14.50
MM5204Q 9.95

HI-TECH

2513-001 (5V) Upper $9.50
2513-005 (5V) Lower 10.95
2513-ADM3 (5V) Lower 14.95
MCM6671 0 ASCI I Shifted 1 2.95
MCM66740 Math Symbol 13.95
MCM66750 Alpha Control 13.45
1771-01 8" & Minifloppy 24.95
1781 Dual Floppy 29.95
1791-01 Dual Floppy 36.95
1791-02 Dual Floppy
1793 DD. DS Floppy
1797 DD, DS Floppy
1691 Data Separator
2143 Clock Generator

8700 8 bit Binary

8701 10 bit Binary
8703 8 bit TS
9400 Volt to Freq Conv.

8750 3'* Oigit BCD 13.95
1408L6 6 bit
1408L8 8 bit
DAC01 D to A

3.95

5.95

DAC08
DAC100
8038 Function Generator 4.50
MC4024 VC0 2.95

LM566VC0 1.95

XR2206 Function Generator 5.25
TR1602B (5V, 12V) 3.95

AY51013 (5V. 12V) 4.95

AY51014A/1612 (5-14V) 6.95
AY51015A/1863 (5V) 6.95

IM6402 7.95

IM6403 8.95

2350 USRT 9.95

1671 B Astros 24.95

MC14411 11.95

4702 14.95

WD1941 9.95

C0M5016
INS8250
AY5-2376
AY5-3600
MM5740AAC

$9.95

16.95

15.95
13.75
13.75

SOCKETS

TO TO

LOW PROFILE
SOCKETS (TIN)

8 pin LP

.16

.15

.14

14 pin LP

.20

.19

.18

1 6 pin LP

.22

.21

.20

1 8 pin LP

.29

.28

.27

20 pin LP

.34

.32

.30

22 pin LP

.29

.27

.24

24 pin LP

.38

.37

.36

28 pin LP

.45

.44

.43

40 pin LP

.60

.59

.58

WIREWRAP

SOCKETS (GOLD)

8 pin WW
10 pin WW (Tin)
14 pin WW
16plnWW
18 pin WW
20 pin WW
22 pin WW
24 pin WW
28 pin WW
40 pin WW

.75

.80

.95

1.15

1.45

1,35

1.80

2.20

.54

.63

.73

.77

.90

1.08

1.35

1.28

1,53

2.09

.49

.58

.87

.70

.81

.99

1.23

1.14

1.38

1.89

| 7400 |

78H05K

$5.95

LM1414N

$1.90

7400 $

.19

7475

$ .38

74161

78M06

1.49

LM1458CN/N

.49

7401

.22

7476

.34

74162

78M.G.

1.49

MC1488N

.99

7402

.22

7479

4.60

74163

LM108AH

2.95

MC1489N

.99

7403

.22

7480

.49

74164

LM300H

.99

LM1496N

.89

7404

.22

7482

.95

74165

LM301CN

.35

LM1556N

1.50

7405

.23

7483

.55

74166

LM304H

1.98

LM1820N

.95

7406

.35

7485

.65

74167

LM305H

1.89

LM1850N

.95

7407

.35

7486

.35

74170

LM306H

3.25

LM1889N

3.10

7408

.26

7489

1.75

74172

LM307CN

.29

LM2111N

1.75

7409

.23

7490

.39

74173

LM308CN

.98

LM2900N

.99

7410

.22

7491

.57

74174

LM309K

1.49

LM2901N

2.50

7411

.29

7492

.45

74175

LM310CN

1.25

LM2917N

2.95

7412

.29

7493

.45

74176

LM311D/CN

.89

CA3013T

2.19

7413

.39

7494

.69

74177

LM312H

1.75

CA3018T

1.99

7414

.59

7495

.65

74179

LM317T

1.70

CA3021T

3.49

7416

.29

7496

.69

74180

LM318CN

1.49

CA3023T

2.99

7417

.29

7497

2.90

74181

LM319N/H

1.25

CA3035T

2.75

7420

.22

74100

2.90

74182

1.29

1.49

3.19

4.95

1.49

1.29

2.99

3.49

1.99
1.30
1.19

2.49
1.19

1.95
.59

1.49

3.95
3.95

3.39
.59

1.19

.98

3.75

3.95
3.75

2.95
1.10
3.70

4.95

5.40
1.25

1.50
.59
.35
.49

74S00 $ .39

74S124

3.69

74S244 $2.99

74S02

.43

74S133

.54

74S251

1.35

74S03

.45

74S134

.66

74S253

1.35

74S04

.52

74S135

1.15

74S257

1.29

74S05

.52

74S136

1.69

74S258

1.29

74S08

.49

74S138

1.29

74S260

.75

74S09

.49

74S139

1.29

74S280

2.79

74S10

.42

74S140

.73

74S287

2.99

74S11

.42

74S151

1.29

74S288

2.55

74S15

.42

74S153

1.29

74S373

3.10

74S20

.42

74S157

1.29

74S374

3.10

74S22

.42

74S158

1.29

74S387

2.75

74S30

.42

74S160

2.79

74S471

7.95

74S32

.49

74S174

1.49

74S472

7.95

74S38

1.19

74S175

1.49

74S473

7.95

74S40

.49

74S188

2.69

74S474

9.95

74S51

.42

74S194

1.89

74S475

9.95

74S64

74S195

1.89

74S570

5.75

74S65

.46

74S196

1.89

74S571

5.75

74S74

.69

74S240

2.75

74S572

8.95

74S86

.72

74S241

2.75

74S573

8.95

74S112

.72

74S242

2.99

74S940

2.90

74S113

' .72

74S243

2.99

74S941

2.90

DIP

SWITCHES

2 Position

4 Position

5 Position

6 Position

1.19

1.29

1.35

7 Position $1 .39

8 Position 1 .49

9 Position 1 .65

10 Position 1.69

MUFFIN® FAN

The dependable, low
cost, largest selling fan
for commercial cooling
applications.

• 105cfm free air delivery

• 4.68" sq. x 1,50" deep,
Weight • 17 oz.

SPECIAL PURCHASE

$9.50...

SUPER 1C CLOSEOUT SPECIALS

14411

$7.96

6571 A

$6.96

8080A CPU

$2.95

5027 CRT

$9.96

4027

.65

4073

.35

74LS668

3/1,99

SIQ 2652

3.95

2102 RAM

.75

2901

3,96

4028

.85

4076

.35

74LS377

2/1.99

8253

6.95

4060 RAM

1.40

8039

3.96

4029

1.29

4078

1.29

74LS241

2/1.99

2768 EPROM

2.95

2732

8.95

MM5320

5.99

4030

.46

4077

.35

8259

6,96

1802

8.95

UPD410

2.98

9131 RAM

1.99

4031

3.25

4078

.35

6661 RAM

2.96

Z80A CPU

4.95

UPD411

2.96

EMM4402

1,99

4032

2.15

4081

.35

LM733CN

3/1.99

8622

6.95

2708 EPROM

8/29.96

10415

4.96

4034

3,25

4082

.35

LM323K

3.96

6502 CPU

5.96

2114

8/14.50

8700 A/D

2/16.95

4036

.95

4085

1.96

7421

7422

7423

7425

7426

7427

7429

7430
7432

7437

7438

7439

7440

7441

7442

7443

7444

7445

7446

7447

7448

7450

7451

7453

7454

7459

7460
7470

7472

7473

7474

.32

.37

1.95

.29

.39

.59

.39

.44

.59

74107
74109
74116

74121

74122

74123

74125

74126
74128
74132
74136
74139

74141 .79

74142 2.95

74143 2.95

74144 2.95

74145 .62

74147 1.95

74148 1.20

74150

74151

74152

74153

74154

74155

74156

74157

74158 1.65

74159 2.49

74160 .88

1.09

.67

.75

74184 2.25

74185 2.25

74186 9.95
74188 3.90

74190 1.15 |

74191

74192

74193

74194

74195

74196

74197

74198 1.39 |

74199
74221
74251
74273 1.05 I
74276 1.8
74279 .7

74283 1.40 I

74284 3.90

74285 3.90
74290 1.25
74298

74365

74366

74367

74368
74390 1.45 I
74393
74490 1.90 I

1.19

.95

74LSOO

74LS00$ .26 74LS1 13$ .43 74LS245S2.20

74LS01

.28

74LS114

.43

74LS247

1.10

74LS02

.28

74LS122

.55

74LS248

1.10

74LS03

.28

74LS123

1.19

74LS249

1.19

74LS04

.35

74LS124

1.35

74LS251

1.40

74LS05

.28

74LS125

.89

74LS253

1.40

74LS08

.28

74LS126

.52

74LS257

.85

74LS09

.35

74LS132

.79

74LS258

.98

74LS10

.28

74LS136

.49

74LS259

2.95

74LS11

.39

74LS138

.85

74LS260

.65

74LS12

.33

74LS139

.85

74LS261

2.49

74LS13

.47

74LS145

1.25

74LS266

.59

74LS14

.95

74LS148

1.49

74LS273

1.75

74LS15

.33

74LS151

.79

74LS275

4.40

74LS20

.26

74LS153

.79

74LS279

.59

74LS21

.33

74LS154

1.70

74LS283

.99

74LS22

.33

74LS155

1.19

74LS290

.99

74LS26

.33

74LS156

.99

74LS293

.99

74LS27

.33

74LS157

.85

74LS295

1.10

74LS28

.33

74LS158

.75

74LS298

1.19

74LS30

.26

74LS160

1.05

74LS324

1.75

74LS32

.33

74LS161

1.15

74LS347

1.95

74LS33

.55

74LS162

1.05

74LS348

1.95

74LS37
74LS38
74LS40
74LS42
74LS47
74LS48
74LS51
74LS54
74LS55
74LS73
74LS74
74LS75
74LS76
74LS78 .45

74LS83A .79

81LS97
81LS98 ...

VOLUME PRICING
CALL

TOLL FREE

4022 1.15

4023 ,29

4024

4025

TOLL FREE

800 - 854-8230

TWX

910-595-1565

Mailorder P.0. Box 17329 Irvine. CA 92713

Retail: 1 31 OB E. Edlnger, Santa Ana CA 92705
(714) 558-8813

542 W. Trimble. San Jose. CA 95131
(408) 946-7010

TERMS: MO. Cashier's Check, Bank Wire. Personal
checks allow 2 weeks lor processing. Include Drivers
License and credit card #s Visa, AMEX. CB add 3%
service charge. Add 3% shipping & handling or $2.50.
whichever Is greater Add 10% lor foreign orders or
US Parcel Post. Include Telephone number NOCODs.
Prices subject to change without notice. Some Items
subject toprlor sale. We reserve the right tosubstltute
manufacturer. Retail prices may vary

CIRCLE 80 ON FREE INFORMATION CARD

125

r fli

RA 64K DYNAMIC tHR T

M M9fl 1 1S 2KX8 static $111 5

■f 1

WH 200 NS V U 1

imiKUID 200 NS Vlllw

STATIC RAMS

I 2101

5101

2102-1

2102L-4

2102L-2

2111

2112

2114

2114L-4

2114L-3

2114L-2

2147

TMS4044-4
TMS4044-3
TMS4044-2
MK4118
TMM2016-200
TMM2016-150
TMM2016-100
HM6116-4
HM6116-3
HM6116-2
I HM6116LP-4
HM6116LP-3
HM6116LP-2
I Z-6132

256 x 4
256 x 4
1024 x 1
1024 x 1
1024 x 1
256 x 4
256 x 4
1024 x 4
1024 x 4
1024 x 4
1024 x 4
4096 x 1
4096 x 1
4096 x 1
4096 x 1
1024 x 8
2048 x 8
2048 x 8
2048 x 8
2048 x 8
2048 x 8
2048 x 8
2048 x 8
2048 x 8
2048 x 8
4096 x 8

(450ns)

(250ns)

(450ns)

(300ns)

(200ns)

(55ns)

(450ns)

(300ns)

(200ns)

(250ns)

(200ns)

(150ns)

(100ns)

(200ns)

(150ns)

(120ns)

(200ns)

(150ns)

(120ns)

(300ns)

(cmos)

(LP)

(cmos)

(cmos)(LP)

(Qstat)

LP Low Power

Qstat Quasi-Static

DYNAMIC RAMS

TMS4027

4096 x 1

(250ns)

1.99

UPD411

4096 x 1

(300ns)

3.00

MM5280

4096 x 1

(300ns)

3.00

MK4108

8192 x 1

(200ns)

1.95

MM5298

8192 x 1

(250ns)

1.85

4116-300

16384 x 1

(300ns)

8/11.75

4116-250

16384 x 1

(250ns)

8/11.95

4116-200

16384 x 1

(200ns)

8/12.95

4116-150

16384 x 1

(150ns)

8/14.95

4116-120

16384 x 1

(120ns)

8/29.95

2118

16384 x 1

(150ns) (5v)

4.95

4164-200

65536 x 1

(200ns) (5v)

5\95

4164-150

65536 x 1

(150ns) (5v)

6.95

5V = single 5 volt supply

EPROMS

1702

256 x 8

(lus)

4.50

2708

1024 x 8

(450ns)

3.95

2758

1024 x 8

(450ns)

(5v)

5.95

2716

2048 x 8

(450ns)

(5v)

3.95

2716-1

2048 x 8

(350ns)

(5v)

5.95

TMS2516

2048 x 8

(450ns)

(5v)

5.50

TMS2716

2048 x 8

(450ns)

7.95

TMS2532

4096 x 8

(450ns)

(5v)

5.95

2732

4096 x 8

(450ns)

(5v)

4.95

2732-250

4096 x 8

(250ns)

(5v)

8.95

2732-200

4096 x 8

(200ns)

(5v)

11.95

2764

8192 x 8

(450ns)

(5v)

9.95

2764-250

8192 x 8

(250ns)

(5v)

14.95

2764-200

8192 x 8

(200ns)

(5v)

24.95

TMS2564

8192 x 8

(450ns)

(5v)

17.95

MC68764

8192 x 8

(450ns)

(5v)(24 pin)

39.95

5v Single 5 Volt Supply

EPROM ERASERS

PE-14

Timer

Capacity

Chip

Intensity

(uW/Cm 2 )

5,200

83.00

PE-14T

5,200

119.00

PE-24T

6,700

175.00

PL-265T

6,700

255.00

PR-125T

15,000

349.00

PR-320

15,000

595.00

Z-80

2.5 Mhz

8000

Z80-CPU

Z80-CTC

3.95 I
4.49 I

Z80-DART

10.95

Z80-DMA

14.95

Z80-PIO

4.49

Z80-SIO/0

16.95

Z80-SIO/1

16.95

Z80-SIO/2

16.95

Z80-SIQ/9

16.95

4.0 Mhz

Z80A-CPU

4.95

Z80A-CTC

4.95

Z80A-DART

11.95

Z80A-DMA

16.95

Z80A-PIO

4.95

Z80A-SIO/0

16.95

Z80A-SIO/1

16.95

Z80A-SIO/2

16.95

Z80A-SIQ/9

16.95

6.0 Mhz

Z80B-CPU

11.95

Z80B-CTC

13.95

Z80B-PIQ

13.95

Z80B-DART 19.95 |

ZILOG

| Z6132 34.95 I

LZ8671

39.95 J

r crystals"

32.768 khz

1.95

1.0 mhz

4.95

1.8432

4.95

2.0

3.95

2.097152

3.95

2.4576

3.95

3.2768

3.95

3.579535

3.95

4.0

3.95

5.0

3.95

5.0688

3.95

5.185

3.95

5.7143

3.95

6.0

3.95

6.144

3.95

6.5536

3.95

8.0

3.95

10.0

3.95

10.738635

3.95

14.31818

3.95

15.0

3.95

16.0

3.95

17.430

3.95

18.0

3.95

18.432

3.95

20.0

3.95

22.1184

3.95

32.0

3.95

CRT

CONTROLLERS

6845

14.95

68B45

19.95

HD46505SP

15.95

6847

11.95

MC1372

6.95

68047

24.95

8275

29.95

7220

99.95

CRT5027

39.95

CRT5037

49.95

TMS9918A

39.95

DP8350

49.95

KEYBOARD

CHIPS

AY5-2376 11.95

LAY5-3600 11.95 ,

• 8 *

8035

8039

INS-8060

INS-8073

8080

8085
8085A-2

8086

8087

8088
8089

8155
8155-2

8156
8185
8185-2
8741
8748
8755

5.95

6.95

17.95

24.95

3.95

5.95

11.95

29.95
CALL

39.95

89.95

6.95

7.95

6.95

29.95 I

39.95 J

39.95

24.95 j
24.95 J

8200

8202

24.95

8203

39.95

8205

3.50

8212

1.80

8214

3.85

8216

1.75

8224

2.25

8226

1.80

8228

3.49

8231

call

8237

19.95

8237-5

21.95

8238

4.49

8243

4.45

8250

10.95

8251

4.49

8253

6.95

8253-5

7.95

8255

4.49

8255-5

5.25

8257

7.95

8257-5

8.95

8259

6.90

8259-5

7.50

8271

39.95

8272

39.95

8275

29.95

8279

8.95

8279-5

10.00

8282

6.50

8283

6.50

8284

5.50

8286

6.50

8287

6.50

8288

25.00

8289

49.95

DISC

CONTROLLERS

1771

16.95

1791

24.95

1793

26.95

1795

49.95

1797

49.95

2791

54.95

2793

54.95

2795

59.95

2797

59.95

6843

34.95

8272

39.95

UPD765

39.95

1691

17.95

2143

18.95

CONNECTORS^

RS232 MALE 2.50 |
RS232 FEMALE 3.25
RS232 HOOD 1.25
>100 ST 3.95 J

JDR Microdevices

1224 S. Bascom Ave. • San Jose, CA 95128
(408) 995-5430 • Telex 171-110

6800

68000

59.95

6800

3.95

6802

7.95

6808

13.90

6809E

19.95

6809

11.95

6810

2.95

6820

4.35

6821

3.25

6828

14.95

6840

12.95

6843

34.95

6844

25.95

6845

14.95

6847

11.95

6850

3.25

6852

5.75

6860

9.95

6862

11.95

6875

6.95

6880

2.25

6883

22.95

68047

24.95

68488

19.95

6800 - 1MHZ

68B00

10.95

68B02

22.25

68B09E

29.95

68B09

29.95

68B10

6.95

68B21

6.95

68B45

19.95

68B50

5.95

68B00 = 2 MHZ

6500

1 MHZ

6502

4.95

6504

6.95

6505

8.95

6507

9.95

6520

4.35

6522

7.95

6532

9.95

6545

22.50

6551

11.85

2 MHZ

6502A

6.95

6522A

9.95

6532A

11.95

6545A

27.95

6551 A

11.95

3 MHZ

6502B

14.95

^UART^^

AY3-1014

6.95

AY5-1013

3.95

AY3-1015

6.95

PT1472

9.95

TR1602

3.95

2350

9.95

2651

8.95

TMS6011

5.95

IM6402

7.95

IM6403

8.95

INS8250

10.95

GENERATORS
BIT-RATE

MC14411

BR1941

4702

COM5016

COM8116

MM5307

11.95

12.95

16.95 j

10.95
10.95

74LS00

.24

74LS173

.69

74LSQ1

.25

74LS174

.55

74LS02

.25

74LS175

.55

74LS03

.25

74LS181

2.15

74LS04

.24

74LS189

8.95

74LS05

.25

74LS190

.89

74LS08

.28

74LS191

.89

74LS09

.29

74LS192

.79

74LS10

.25

74LS193

.79

74LS11

.35

74LS194

.69.

74LS12

.35

74LS195

.69

74LS13

.45

74LS196

.79

74LS14

.59

74LS197

.79

74LS15

.35

74LS221

.89

74LS20

.25

74LS240

.95

74LS21

.29

74LS241

.99

74LS22

.25

74LS242

.99

74LS26

.29

74LS243

.99

74LS27

.29

74LS244

.99

74LS28

.35

74LS245

1.49

74LS30

.25

74LS247

.75

74LS32

.29

74LS248

.99

74LS33

.55

74LS249

.99

74LS37

.35

74LS251

.59

74LS38

.35

74LS253

.59

74LS40

.25

74LS257

.59

74LS42

.49

74LS258

.59

74LS47

.75

74LS259

2.75

74LS48

.75

74LS260

.59

74LS49

.75

74LS266

.55

74LS51

.25

74LS273

1.49

74LS54

.29

74LS275

3.35

74LS55

.29

74LS279

.49

74LS63

1.25

74LS280

1.98

74LS73

.39

74LS283

.69

74LS74

.35

74LS290

.89

74LS75

.39

74LS293

.89

74LS76

.39

74LS295

.99

74LS78

.49

74LS298

.89

74LS83

.60

74LS299

1.75

74LS85

.69

74LS323

3.50

74LS86

.39

74LS324

1.75

74LS90

.55

74LS352

1.29

74LS91

.89

74LS353

1.29

74LS92

.55

74LS363

1.35

74LS93

.55

74LS364

1.95

74LS95

.75

74LS365

.49

74LS96

.89

74LS366

.49

74LS107

.39

74LS367

.45

74LS109

.39

74LS368

.45

74LS112

.39

74LS373

.99

74LS113

.39

74LS374

.99

74LS114

.39

74LS377

1.39

74LS122

.45

74LS378

1.18

74LS123

.79

74LS379

1.35

74LS124

2.90

74LS385

1.90

74LS125

.49

74LS386

.45

74LS126

.49

74LS390

1.19

74LS132

.59

74LS393

1.19

74LS133

.59

74LS395

1.19

74LS136

.39

74LS399

1.49

74LS137

.99

74LS424

2.95

74LS138

.55

74LS447

.37

74LS139

.55

74LS490

1.95

74LS145

1.20

74LS624

3.99

74LS147

2.49

74LS640

2.20

74LS148

1.35

74LS645

2.20

74LS151

.55

74LS668

1.69

74LS153

.55

74LS669

1.89

74LS154

1.90

74LS670

1.49

74LS155

.69

74LS674

9.65

74LS156

.69

74LS682

3.20

74LS157

.65

74LS683

3.20

74LS158

.59

74LS684

3.20

74LS160

.69

74LS685

3.20

74LS161

.65

74LS688

2.40

74LS162

.69

74LS689

3.20

74LS163

.65

74LS783

24.95

74LS164

.69

81LS95

1.49

74LS165

.95

81LS96

1.49

74LS166

1.95

81LS97

1.49

74LS168

1.75

81LS98

1.49

74J.S169

1.75

25LS2521

2.80

74LS170

1.49

25LS2569

4.25

1983 JDR MICRODEVICES, INC.

FUNCTION

MC4024 3.95

LM566 1.49

XR2206 3.75

L8038 3.95 ,

VISIT OUR RETAIL STORE

HOURS: M-W-F, 9-5 T-Th., 9-9 Sat. 11-3

PLEASE USE YOUR CUSTOMER NUMBER WHEN ORDERING
TERMS: For shipping include $2 for UPS Ground or S3 for UPS Blue
Label Air Items over 5 pounds require additional shipping charges.
Foreign orders, include sufficient amount for shipping. There is a $10
minimum order. Bay Area and Los Angeles Counties add 6V 2 °/o Sales
Tax. Other California residents add 6% Sales Tax. We reserve the
right to substitute manufacturer. Not responsible for typographical
errors. Prices are subject to change without notice. We will match or
beat any competitor's price provided it is not below our cost.

UHCLt 49 ON FREE INFORMATION CARD

7400

.19

74132

.45

7401

.19

74136

.50

7402

.19

74141

.65

7403

.19

74142

2.95

7404

.19

74143

2.95

7405

.25

74145

.60

7406

.29

74147

1.75

7407

.29

74148

1.20

7408

.24

74150

1.35

7409

.19

74151

.55

7410

.19

74152

.65

7411

.25

74153

.55

7412

.30

74154

1.25

7413

.35

74155

.75

7414

.49

74156

.65

7416

.25

74157

.55

7417

.25

74159

1.65

7420

.19

74160

.85

7421

.35

74161

.69

7422

.35

74162

.85

7423

.29

74163

.69

7425

.29

74164

.85

7426

.29

74165

.85

7427

.29

74166

1.00

7428

.45

74167

2.95

7430

.19

74170

1.65

7432

.29

74172

5.95

7433

.45

74173

.75

7437

.29

74174

.89

7438

.29

74175

.89

7440

.19

74176

.89

7442

.49

74177

.75

7443

.65

74178

1.15

7444

.69

74179

1.75

7445

.69

74180

.75

7446

.69

74181

2.25

7447

.69

74182

.75

7448

.69

74184

2.00

7450

.19

74185

2.00

7451

.23

74190

1.15

7453

.23

74191

1.15

7454

.23

74192

.79

7460

.23

74193

.79

7470

.35

74194

.85

7472

.29

74195

.85

7473

.34

74196

.79

7474

.33

74197

.75

7475

.45

74198

1.35

7476

.35

74199

1.35

7480

.59

74221

1.35

7481

1.10

74246

1.35

7482

.95

74247

1.25

7483

.50

74248

1.85

7485

.59

74249

1.95

7486

.35

74251

.75

7489

2.15

74259

2.25

7490

.35

74265

1.35

7491

.40

74273

1.95

7492

.50

74276

1.25

7493

.35

74279

.75

7494

.65

74283

2.00

7495

.55

74284

3.75

7496

.70

74285

3.75

7497

2.75

74290

.95

74100

1.75

74293

.75

74107

.30

74298

.85

74109

.45

74351

2.25

74110

.45

74365

.65

74111

.55

74366

.65

74116

1.55

74367

.65

74120

1.20

74368

.65

74121

.29

74376

2.20

74122

.45

74390

1.75

74123

.49

74393

1.35

74125

.45

74425

3.15

74126

.45

74426

.85

74128

.55

74490

2.55

LM301

.34

LIN

LM340 (see 7800)

LM301H

.79

LM348

.99

LM307

.45

LM350K

4.95

LM308

.69

LM350T

4.60

LM308H

1.15

LM358

.69

LM309H

1.95

LM359

1.79

LM309K

1.25

LM376

3.75

LM310

1.75

LM377

1.95

LM311

.64

LM378

2.50

LM311H

.89

LM379

4.50

LM312H

1.75

LM380

.89

LM317K

3.95

LM380N-8 1.10

LM317T

1.19

LM381

1.60

LM318

1.49

LM382

1.60

LM318H

1.59

LM383

1.95

LM319H

1.90

LM384

1.95

LM319

1.25

LM386

.89

LM320 (see 7900)

LM387

1.40

LM322

1.65

LM389

1.35

LM323K

4.95

LM390

1.95

LM324

.59

LM392

.69

LM329

.65

LM394H

4.60

LM331

3.95

LM399H

5.00

LM334

1.19

NE531

2.95

LM335

1.40

NE555

.34

LM336

1.75

NE556

.65

LM337K

3.95

NE558

1.50

LM337T

1.95

NE561

24.95

LM338K

6.95

NE564

2.95

LM339

.99

LM565

.99

H = TO-5 CAN

LM566

1.49

LM1800

2.37

LM567

.89

LM1812

8.25

NE570

3.95

LM1830

3.50

NE571

2.95

LM1871

5.49

NE592

2.75

LM1872

5.49

LM709

.59

LM1877

3.25

LM710

.75

LM1889

1.95

LM711

.79

LM1896

1.75

LM723

.49

ULN2003

2.49

LM723H

.55

LM2877

2.05

LM733

.98

LM2878

2.25

LM741

.35

LM2900

.85

LM741N-14

.35

LM2901

1.00

LM741H

.40

LM3900

.59

LM747

.69

LM3905

1.25

LM748

.59

LM3909

.98

LM1014

1.19

LM3911

2.25

LM1303

1.95

LM3914

3.95

LM1310

1.49

LM3915

3.95

MC1330

1.69

LM3916

3.95

MC1349

1.89

MC4024

3.95

MC1350

1.19

MC4044

4.50

MC1358

1.69

RC4136

1.25

MC1372

6.95

RC4151

3.95

LM1414

1.59

LM4250

1.75

LM1458

.59

LM4500

3.25

LM1488

.69

RC4558

.69

LM1489

.69

LM13080

1.29

LM1496

.85

LM13600

1.49

LM1558H

3.10

LM13700

1.49

TO-220

= TO-3

74S00

IC SOCKETS

74S00

.32

74S163

1.95

74S02

.35

74S168

3.95

74S03

.35

74S169

3.95

74S04

.35

74S174

.95

74S05

.35

74S175

.95

74S08

.35

74S181

3.95

74S09

.40

74S182

2.95

74S10

.35

74S188

1.95

74S11

.35

74S189

6.95

74S15

.35

74S194

1.49

74S20

.35

74S195

1.49

74S22

.35

74S196

1.49

74S30

.35

74S197

1.49

74S32

.40

74S201

6.95

74S37

.88

74S225

7.95

74S38

.85

74S240

2.20

74S40

.35

74S241

2.20

74S51

.35

74S244

2.20

74S64

.40

74S251

.95

74S65

.40

74S253

.95

74S74

.50

74S257

.95

74S85

1.99

74S258

.95

74S86

.50

74S260

.79

74S112

.50

74S274

19.95

74S113

.50

74S275

19.95

74S114

.55

74S280

1.95

74S124

2.75

74S287

1.90

74S132

1.24

74S288

1.90

74S133

.45

74S289.

6.89

74S134

.50

74S301

6.95

74S135

.89

74S373

2.45

74S138

.85

74S374

2.45

74S139

.85

74S381

7.95

74S140

.55

74S387

1.95

74S151

.95

74S412

2.98

74S153

.95

74S471

4.95

74S157

.95

74S472

4.95

74S158

.95

74S474

4.95

74S161

1.95

74S482

15.25

74S162

1.95

74S570

2.95

74S571

2.95

1-99

100

.13

.11

.15

.12

.17

.08

.20

.18

.29

.27

.30

.27

.30

.27

.40

.32

.49

.39

4.25

call

ST =

SOLDERTAIL

.59

.49

.69

.52

.49

.99

.90

1.09

.98

1.39

1.28

1.49

1.35

1.69

1.49

1.99

1.80

= WIREWRAP

ZIF

6.75

call

24 pin ZIF 9.95 call
28 pin ZIF 10.95 call
ZIF = TEXTOOL
(Zero Insertion Force)

I LED LAMPS!

CA 3023
CA 3039
CA 3046
CA 3059
CA 3060
CA 3065
CA 3080
CA 3081

RCA

CA 3082
CA 3083
CA 3086
CA 3089
CA 3096
CA 3130
CA 3140
CA 3146
1.19

CMOS

TL494

4.20

75365

1.95

TL496

1.65

75450

.59

TL497

3.25

75451

.39

75107

1.49

75452

.39

75110

1.95

75453

.39

75150

1.95

75454

.39

75154

1.95

75491

.79

75188

1.25

75492

.79

75189

1.25

75493

.89

75494

.89

FET

TL071

.79

TL084

2.19

TL072

1.19

LF347

2.19

TL074

2.19

LF351

.60

TL081

.79

LF353

1.00

TL082

1.19

LF355

1.10

TL083

1.19

LF356

1.10

LF357

1.40

VOLTAGE
REGULATORS

7805T

.75

7905T

.85

7808T

.75

7908T

.85

7812T

.75

7912T

.85

7815T

.75

7915T

.85

7824T

.75

7924T

.85

7805K

1.39

7905K

1.49

7812K

1.39

7912K

1.49

7815K

1.39

7915K

1.49

7824K

1.39

7924K

1.49

78L05

.69

79L05

.79

78L12

.69

79L12

.79

78L15

.69

79L15

.79

78H05K

9.95

LM323K

4.95

78H12K

9.95

UA78S40

1.95

T =

TO-220

K = TO-3

L = TO-92

1-99

100-up

Red

.10

.09

Green

.18

.15

Yellow

.18

.15

DIP
SWITCHES I

I 4 POSITION .85

5 POSITION .90

6 POSITION .90

7 POSITION .95 |
l 8 POSITION

LED DISPLAYS

\ CLOCK

r INTERSIL 1

r 9000

CIRCUITS

ICL7103

9.50

9316

1.00

MM5314

4.95

ICL7106

9.95

9334

2.50

MM5369

3.95

ICL7107

12.95

9368

3.95

MM5375

4.95

ICL7660

2.95

9401

9.95

MM58167

8.95

ICL8038

3.95

9601

.75

MM58174

11.95

ICM7207A

5.59

1 9602

1.50

i MSM5832

6.95 i

i ICM7208

15.95 j

L 96S02

1.95 J

HP 5082-7760

.6"

1.29

MAN 72

.3"

.99

MAN 74

.3"

.99

FND-357 (359)

.375"

1.25

FND-500 (503)

.5"

1.49

FND-507 (510)

.5"

1.49

EXAR

XR 2206
XR 2207
XR 2208
XR 2211
. XR 2240

INTERFACE

8T26
8T28
8T95
8T96
8T97
8T98
DM8131
DP8304
DS8835
DS8836

MISC.

ULN2003
3242
3341
MC3470
MC3480
11C90
95H90

2513-001 UP
k 2513-002 LOW

DATA ACQUISITION

ADC0800 15.55 DAC0808

ADC0804 3.49 DAC1020

ADC0809 4.49 DAC1022

ADC0817 9.95 MC1408L6

^ DAC0800 4.95 MC1408L8

4000

.29

4527

1.95

4001

.25

4528

1.19

4002

.25

4531

.95

4006

.89

4532

1.95

4007

.29

4538

1.95

4008

.95

4539

1.95

4009

.39

4541

2.64

4010

.45

4543

1.19

4011

.25

4553

5.79

4012

.25

4555

.95

4013

.38

4556

.95

4014

.79

4581

1.95

4015

.39

4582

1.95

4016

.39

4584

.75

4017

.69

4585

.75

4018

.79

4702

12.95

4019

.39

74C00

.35

4020

.75

74C02

.35

4021

.79

74C04

.35

4022

.79

74C08

.35

4023

.29

74C10

.35

4024

.65

74C14

.59

4025

.29

74C20

.35

4026

f.65

74C30

.35

4027

.45

74C32

.39

4028

.69

74C42

1.29

4029

.79

74C48

1.99

4030

.39

74C73

.65

4034

1.95

74C74

.65

4035

.85

74C76

.80

4040

.75

74C83

1.95

4041

.75

74C85

1.95

4042

.69

74C86

.39

4043

.85

74C89

4.50

4044

.79

74C90

1.19

4046

.85

74C93

1.75

4047

.95

74C95

.99

4049

.35

74C107

.89

4050

.35

74C150

•5.75

4051

.79

74C151

2.25

4053

.79

74 Cl 54

3.25

4060

.89

74C157

1.75

4066

.39

74C160

1.19

4068

.39

74C161

1.19

4069

.29

74C162

1.19

4070

.35

74C163

1.19

4071

.29

74C164

1.39

4072

.29

74C165

2.00

4073

.29

74C173

.79

4075

.29

74C174

1.19

4076

.79

74C175

1.19

4078

.29

74C192

1.49

4081

.29

74C193

1.49

4082

.29

74C195

1.39

4085

.95

74C200

5.75

4086

.95

74C221

1.75

4093

.49

74C373

2.45

4098

2.49

74C374

2.45

4099

1.95

74C901

.39

14409

12.95

74C902

.85

14410

12.95

74C903

.85

14411

11.95

74C905

10.95

14412

12.95

74C906

.95

14419

7.95

74C907

1.00

14433

4.18

74C908

2.00

4502

.95

74C909

2.75

4503

.65

74C910

9.95

4508

1.95

74C911

8.95

4510

.85

74C912

8.95

4511

.85

74C914

1.95

4512

.85

74C915

1.19

4514

1.25

74C918

2.75

4515

1.79

74C920

17.95

4516

1.55

74C921

15.95

45ie

.89

74C922

4.49

4519

.39

74C923

4.95

4520

.79

74C925

5.95

4522

1.25

74C926

7.95

4526

1.25

74C928

7.95

74C929

19.95 ,

SOUND CHIPS

76477 3.95

76489 8.95

AY3-8910 12.95

AY3-8912 12.95

L MC3340 1.49 J

ORDER TOLL FREE 800-538-5000 800-662-6279

ALL MERCHANDISE P—'T r— I (CALIFORNIA RESIDENTS)

100% GUARANTEED FT2 CALL US FOR VOLUME QUOTES

1983 JDR MICRODEVICES, INC.

CIRCLE 49 ON FREE INFORMATION CARD

CABINETS FOR SVo"
DISK DRIVES
CABINET #1 $ 29.95

★ DIMENSIONS 8 5 /s x 5'** x 3 ,5 />e"

★ COLOR MATCHES APPLE

★ FITS STANDARD 5'/." DRIVES, INCL.
SHUGART

★ INCLUDES MOUNTING
HARDWARE AND FEET

CABINET #2 $ 79.00

★ COMPLETE WITH POWER SUPPLY,
SWITCH, LINE CORD. FUSE &
STANDARD POWER CONNECTOR

★ DIMENSIONS: 11V* x 5K x 3 ,5 /ie"

★ +5V @ 1 AMP, + 12V @ 1.5 AMP

★ FITS STANDARD 5'A" DRIVES

★ PLEASE SPECIFY GRAY OR TAN
NOTE: Please include sufficient amount for
shipping on above items.

RESISTORS

V» WATT 5% CARBON FILM ALL
STANDARD VALUES
FROM 1 OHM TO 10 MEG OHM
50 PCS. SAME VALUE .025

100 PCS. SAME VALUE .02

1000 PCS. SAME VALUE .015

BYPASS CAPS

.01 UF DISC 100/6.00

.1 UF DISC 100/8.00

.1 UF MONOLITHIC 100/15.00

CONNECTORS

RS232 MALE

2.50

RS232 FEMALE

3.25

RS232 FEMALE

RIGHT ANGLE 5.25

RS232 HOOD

1.25

S-100 ST

3.95

S-100 WW

4.95

44 pin ST

2.95

44 pin WW

4.95

72 pin ST

6.95

72 pin WW

7.95

SWITCHES

SPDT

mini-toggle

1.25

DPDT

mini-toggle

1.50

SPDT

push-button

1.49

OPTO-

ISOLATORS

MCA-7

1.50

MCA-255

1.75

IL-1

1.25

ILA-30

1.25

ILQ-74

2.75

H11C5

1.25

TIL-111

1.00

TIL-113

1.75

4N26

1.00

4N27

1.10

4N28

.69

4N33

1.75

4N35

1.25

4N37

1.25

MCT-2

1.00

MCT-6

1.50

HIE HAVE THE C0NIPLETE LIKE OF
DISC. TAHTALUm AHD ELECTROLYTIC
CAPACITORS IH STOCK!

TRANSISTORS 1

2N918

.50

2N3772

1.85

MPS918

.25

2N3903

.25

2N2102

.50

2N3904

.10

2N2218

.50

2N3906

.10

2N2218A

.50

2N4122

.25

2N2219

.50

2N4123

.25

2N2219A

.50

2N4249

.25

2N2222

.25

2N4304

.75

PN2222

.10

2N4401

.25

MPS2369

.25

2N4402

.25

2N2484

.25

2N4403

.25

2N2905

.50

2N4857

1.00

2N2907

.25

PN4916

.25

PN2907

.125

2N5086

.25

2N3055

.79

PN5129

.25

3055T

.69

PN5139

.25

2N3393

.30

2N5209

.25

2N3414

.25

2N6028

.35

2N3563

.40

2N6043

1.75

2N3565

.40

2N6045

1.75

PN3565

.25

MPS-A05

.25

MPS3638

.25

MPS-A06

.25

MPS3640

.25

MPS-A55

.25

PN3643

.25

TIP29

.65

PN3644

.25

TIP31

.75

MPS3704

.15

TIP32

.79

MPS3706

.15

MICROCOMPUTER
HARDWARE HANDBOOK

FROM ELCOMP — $14.95

Over 800 pages of manufacturers

data sheets on

most commonly

used IC’s.

Includes:

★ TTL -

74/74LS and 74F

★ CMOS

★ Voltage Regulators

★ Memory — RAM, ROM, EPROM

★ CPU’s-

- 6800, 6500, Z80, 8080,

8085, 8086/8

★ MPU support & interface -

^ 6800, 6500, Z80, 8200, etc.

HEAT SINKS

TO-3 style

.95

^TO-220 style

.35

DISK DRIVES

TANDON

TM100-1 5' 4 " (FOR IBM) SS/DD 229.00
TM100-2 5’ 4" (FOR IBM) DS/DD 295.00
SHUGART

SA 400 L 5' 4 " (40 TRACK) SS/DD 199.95
SA 400 5’ 4 ." (35 TRACK) SS/DD 189.95
SIEMENS

FD100-8 8" SS/DD

(801 REPLACEMENT) Z59.UU

PERTEC

FD-200 5 ss/DD 179.95

FD-250 5v ds/dd 199.95

MPI

MP-52 5’/4" (FOR IBM) DS/DD 295.00

POWER SUPPLY

MODEL 2 $ 39 95

MOUNTED ON PC BOARD
MANUFACTURED BY CONVER
+5 VOLT 4 AMP
±12 VOLT 1 AMP

NOTE: Please include sufficient amount for
shipping on above items.

DIODES

1N751

5.1 volt zener

.25

1N759

12.0 volt zener

.25

1N4148

(1N914) switching

25/1.00

1N4004

400PIV rectifier

10/1.00

KBP02

200PIV 1.5amp bridge

.45

KBP04

400PIV 1.5amp bridge

.55

D-SUBMINIATURE

DESCRIPTION

SOLDER

RIGHT ANGLE
SOLDER

RIBBON CABLE.

HOODS

MALE

FEMALE

MALE

FEMALE

MALE

FEMALE

BLACK

GREY

ORDER BY

DBxxP

DBxxS

DBxxPR

DBxxSR

IDBxxP

IDBxxS

HOOD-B

HOOD

CONTACTS 9

2.08

2.66

1.65

2.18

3.37

3.69

—

1.60

2.69

3.63

2.20

3.03

4.70

5.13

—

1.60

2.50

3.25

3.00

4.42

6.23

6.84

1.25

4.80

7.11

4.83

6.19

9.22

10.08

—

2.95

6.06

9.24

—

3.50

For order instructions see “IDC Connectors" below.

RIBBON CABLE

CONTACTS

SINGLE COLOR

COLOR CODED

10'

.50

4.40

.83

7.30

.65

5.70

1.25

11.00

.75

6.60

1.32

11.60

.98

8.60

1.65

14.50

1.32

11.60

1.92

16.80

1.38

12.10

2.50

22.00

IDC CONNECTORS

DESCRIPTION

SOLDER HEADER

RIGHT ANGLE
SOLDER HEADER

WW HEADER

RIGHT ANGLE
WW HEADER

RIBBON

HEADER SOCKET

RIBBON

HEADER

RIBBON

EDGE CARD

ORDER BY

IDHxxS

IDHxxSR

IDHxxW

IDHxxWR

IDSxx

IDMxx

IDExx

CONTACTS 10

.82

.85

1.86

2.05

1.15

2.25

1.29

1:35

2.98

3.28

1.86

5.50

2.36

1.68

1.76

3.84

4.22

2.43

6.25

2.65

2.20

2.31

4.50

4.45

3.15

7.00

3.25

2.58

2.72

5.28

4.80

3.73

7.50

3.80

3.24

3.39

6.63

7.30

4.65

8.50

4.74

ORDERING INSTRUCTIONS: Insert the number of contacts in the position marked "xx" of the "order by" part number listed. Example: A 10 pin right angle solder style
header would be IDH10SR.

JDR Microdevices

1224 S. Bascom Ave. • San Jose, CA 95128
(408) 995-5430 • Telex 171-110

VISIT OUR RETAIL STORE

HOURS: M-W-F, 9-5 T-Th., 9-9 Sat.

c 1983 JDR MICRODEVICES, INC.

Sat. 11-3

PLEASE USE YOUR CUSTOMER NUMBER WHEN ORDERING
TERMS: For shipping include $2 for UPS Ground or $3 for UPS Blue
Label Air. Items over 5 pounds require additional shipping charges.
Foreign orders, include sufficient amount for shipping. There is a $10
minimum order. Bay Area and Los Angeles Counties add 6V 2 % Sales
Tax. Other California residents add 6% Sales Tax. We reserve the
right to substitute manufacturer. Not responsible for typographical
errors. Prices are subject to change without notice. We will match or
beat any competitor’s price provided it is not below our cost.

CIRCLE 49 ON FREE INFORMATION CARD

SPRING APPLE SALE!

FD-35 DISK DRIVE

By MA Systems

★ Direct Replacement for
Apple Disk II

| ★ Compatible with Apple
Controller or other Apple
compatible controllers
| ★ Specially designed electronics
with low power consumption
| ★ DOS 3.3 and 3.2 compatible
1* Owner’s Manual and Warranty
Card included

★ 90-day Warranty

NEU)

INTRODUCTORY

CONTROLLER CARD *89.95 J

$22995

[APPLE II KEYBOARD *99.95^

From the Keyboard Co.

★ Brand New Rev. 7 keyboard —
NOT an imitation

★ Special Purchase — Supply
very limited

| ★ Includes Encoder Board and
Cable '

APPLE COMPATIBLE
POWER SUPPLY *99.95

I* Compact Switching Design

★ All Outputs regulated
| ★ Short Circuit and Overload

Protection

| ★ Complete with Apple-type
plug-in power cord
|* Apple Compatible — Yethigher |
output allows more disk drives
and cards without overheating
|* +5V @ 5A, +12V @ 3A,

-5 V @ ,5A, -12V @ ,5A
|* Shielded enclosure: 10%" x-3Vfe"
x 2% e"

VIEWMAX 80

A Full Function 80 column card
for Apple II*

2 YEAR WARRANTY

NEW IMPROVED

I JDR COOLING FAN

FOR YOUR APPLE II

| ★ Easy modification — no

modification of Apple required
!★ Eliminates overheating
problems

| ★ Switch on front controls fan,
Apple, and extra outlet
| ★ Rotron whisper fan is the
quietest, most reliable on the
market

NOW WITH SURGE
SUPPRESSION
$69.95

L WITHOUT SURGE SUPPRESSION *59.95 J

INTERFACE CARDS

By Perisoft
PRINTERLINK *79.00

★ Centronics Standard Parallel
Interface for Apple II

[ ★ Simple to use — Yet supports
custom driver applications
from ROM or Disk
| ★ Includes card, cable and user’s |
manual

[ ★ 1 Year Warranty

MESSENGER *119.00

★ Serial I/O for Apple II

★ Connects virtually any RS-232
serial device

★ 6 switch selectable drivers:

4 printer drivers
Terminal Driver — 40 or 80
driver

★ Includes card, cable and user’s
manual

L* 1 Year Warranty

[JDR 16K RAMCARD]

For Apple II*

★ Expand your 48K Apple to 64K

★ Fully compatible with Apple
Language System — Use in
place of Apple Language card

★ Provides extra memory for
Visicalc™

★ Run PASCAL, FORTRAN,
Integer Basic with appropriate
software

★ Highest quality card features:
gold edge connector, sockets
for all IC’s

NOW WITH 2 YEAR WARRANTY

$4495
$4095
$-|495

ASSEMBLED & TESTED
WITH WARRANTY

KIT — INCLUDES ALL
PARTS & INSTRUCTIONS. . .

BARE PC CARD
L WITH INSTRUCTIONS

f MONITORS 1

GREEN PHOSPHOR

NEC JB1201M

$ 169 00

ZENITH zvM-121

$ 119 00

COLOR

[AMDEK COLOR 1

$ 335°°J

IF V0U CAN FIND A PRICE LOWER
ELSEWHERE. LET US RN0W AND
WE WILL NIEET OR BEAT THEIR
PRICE! (SEE TERHIS BELOW)

$19995

OKIDATA PRINTERS

★ 120 cps, 9x9 Dot Matrix

★ 50% faster than EPSON

★ Parallel and Serial interfaces
are standard

ML-82A *479 50

ML-83A *699 95

ML-84 PARALLEL . . . *1059°°

CALL FOR PRICES ON 82A TRACTOR OPTION I
AND 82A, 83A GRAPHICS OPTION. CABLES]
, AND INTERFACE CARDS AVAILABLE

5'U" DISKETTES

ATHANA SS SD SOFT . . . 24.95
MEMOREX ss SD SOFT 26.95
VERBATIM SS DD SOFT 29.95
VERBATIM 10 SECT hard 29.95

NASHUA

TOP QUALITY — LOW PRICE!

Single Sided, Single Density
Soft Sectored with Hub Ring

$19.95 box of 10

ORDER TOLL FREE 000-530-5000

ALL MERCHANDISE
100% GUARANTEED

> 1983 JDR MICRODEVICES, INC.

000 000-662-6270

(CALIFORNIA RESIDENTS)
CALL US FUR VULUME QUOTES

* APPLE IS A TRADEMARK OF APPLE COMPUTER CO.

CIRCLE 49 ON FREE INFORMATION CARD

RADIO-ELECTRONICS

FACTORY PRIME
DEVICES INCLUDE:

• Capacitors

all types & styles

• Chokes & Coils

• Connectors

• Digital & Linear IC’s

• Hardware & Accessories

• 1C Sockets

• Memory

• Microwave Semiconductors

• Resistors
fixed & variable

• Transformers

PLEASE SEND ME

(Quantity) MC100A(s) @ $79.95 U.S. (Canadian residents send $89.95 CDN.) $_

Ontario residents add 7% PST $_

Postage — $2.25 for U.S. $1 .85 for Canada (per instrument) $.

□ I ENCLOSE CHECK □ MONEY ORDER □ BILL MY VISA TOTAL $.

□ VISA CARD NO. EXPIRY DATE SIGNATURE

Immediate shipping on orders with money orders or VISA.

Personal checks please allow 2 to 3 weeks for clearance.

NAME

ADDRESS _
CITY

_ ZIP CODE _

MAIL TO DAETRON 935 THE QUEENSWAY BOX 641
TORONTO ONTARIO M8Z 5Y9

CIRCLE 12 ON FREE INFORMATION CARD

CORPORATION

SEMICONDUCTOR PARTS & PRODUCTS

MICROWAVE TV ANTENNA SYSTEMS |

Freq. 2.1 to 2.6 GHz . 34 db Gain +

-j COMPLETE SYSTEMS

A't,. . (as Pictured)

j Commercial 40"

J | Rod Style $109.95

/ J Parabolic 20"

Dish Style $ 99.95

I COMPONENTS

w 'HP Down Converters

- - (both types) S 34.95

TWO YEAR WARRANTY Power Supplies

PARTS & LABOR (12V to 16V) $ 24.95

Data Info (Plans) $ 9.95

X CALL OR WRITE FOR

/ KITS. PARTS. INDIVIDUAL

/ COMPONENTS

WHY SPEND A FORTUNE ON A

DIGITAL CAPACITANCE

METER?

As a matter of fact you don’t have to pay
$180 to $500 and up anymore for a Digital
Capacitance Meter that is both depen-
dable and rugged with good accuracy.
The MCI 00 A comes completely assembl-
ed and calibrated and at $79.95 is an
outstanding value. The extensive range of
30 pF to 9,999 uF (no external meters re-
quired) and true hand held portable size
(only 4 3 /4” x 2 V 2 ” x IV 2 ”) make the
MC100A an extremely practical and easy
to use instrument for the hobbyist techni-
cian or engineer.

CHECK THESE OTHER FEATURES

* Basic accuracy 2% (± one count) on
pF, nF ranges, 5% (± one count) on uF
range.

•Uses single 9V battery (not included).
•Decimal points light up when battery is
low or when capacitor is overrange.

‘Full 4 digit high efficiency LED display
uses special circuitry to save on batteries.
•Maximum conversion time for 9,999 uF
is less than 6 seconds.

•Constructed with a tough impact resis-
tant plastic case.

*90 day parts and labour warranty.

• Transistors & MORE!

MANUFACTURERS SUCH AS: Motorola, National, NEC,
J.W. Miller, Texas Instruments and more!

WE STOCK & SUPPLY DEVICES FOR: OEM s,

Distributors, Hobbiests, Magazine Projects, Engineers,
Schools, Technicians & You!

Call or Write for Quantity Pricing
and FREE Catalog.

PHoenix, AZ 85067 ( 602 ) 274-2885

We Repair All Types Down
Converters & Power Supplies

DAETRON

935 THE QUEENSWAY, BOX 641
TORONTO, ONTARIO M8Z 5Y9
(416) 499-7221

DEALER ENQUIRIES INVITED

Phillips-Tech

Electronics

P.0. BOX 34772
Phoenix, AZ 85067
(602) 265-8255

Special Quantity Pricing
Dealers Wanted

ICROX:
RflT x

508 Central Ave.
Westfield, N.J. 07090
' (201)6 54-6008 /

o><d

UHF-TV PREAMP

_ featured in Radio Electronics March/
lay articles, 1982)

This inexpensive antenna mounted pre-
amp can add more than 25 dB of gam to
your system. Lots of satisfied customers
and repeat orders for this high quality kit,
which includes all component parts, PC
BD, Case, Power Supply and Baiun $34.50
Assembled Version $57.50

APPLE

Heart Rate Monitor KIT-S39.95

Hava Soma Fun... Fun... Fun!

PROGRAMMABLE MESSAGES
IN SPACE, with SPACE WRITER

Kit $39.50

Signalman Mark I Modem-$99

Direct connect modem/RS-232C; Built in
interface cable and connector; Light, com-
pact, Bell 103 compatible Data/voice switch

BMC-12A,

12" Green Phosphor Monitor $99

2N3053 (PRIME) 2/91

2N3791 (PRIME) 2/*I

333’ S (TELEDYNE 333) 3/91

2716 EPROM (430n»> *3.85

MPS 6371 (NPN SILICON TRANS) 10/91

"QQOT" SOLDERING IR0N(20w) *9

"BOOT" SOLDER SUCKER (work* great). 9 12

LMI310 3/92

CD4047 2/*3

RF CHOKE lOuH 1/2W FIXED ...3/92

LM1889 2/94

BNC “T" CONNECTOR *1

20V 1W EXPOXY ZENERS 20/*l

7BL08 <5V REGULATOR) 5/91

MOTION DETECTOR BOARDS-92 EACH. .7/910
MOTION DETECTOR ( IC 0NLY)3/*2. . .20/910

CONDENSER MICROPHONE 3/92

9V BATTERIES 2/91

1000 PIECE RESISTOR ASS’T 1/2W 93

CRYSTALS- 1 MHz . . 92-3. 3MHz . . 91 /6MHz . . 92

2560.0 KC 91

. 22uF 30V SUB MINI EPOXY DISC... 20/91

. 33uF 100V DIP MYLAR B/91

47uF 25V MINI RADIAL 3/91

4. 7uF 40V MINI RADIAL 10/91

6. 8uF 33V SOLID TANTALUM 2/91

lOuF 30 v DIP TANTALUM 3/92

3200uF 50V TWIST LOCK 3/92

UOOOuF 50V (COMP GRADE MALLORY) 92

lOOOuF 16V TWIST LOCK 2/91

VINYL COATED (FIBERGLASS REINFORCED)
SLEEVING- 1 ’ LENGTHS, 10 DIAMETERS. .. 93
LED (HIGH INTENS. RED EMITTER, WATER
CLEAR LENS) 10/91, 100/97.50, 1000/969

BATTERY SNAPS 5/91

HEAVY DUTY ALLIGATOR CLIPS 10/93

LIGHTER WEIGHT CLIPS 10/92

74LS174 (PRIME TEXAS INST) 2/91

VERY LOUD BUZZER 2/91

SN75324 IC 3/91

LM1391 (PRIME, HOUSE *D> 3/91

ULN 2001 (UNTESTED) 10/91

RS232 CONNECTOR ( DB-25P-A 123) 93

lOOK TRIMPOT .4/91

10K TRIMPOT 4/91

SN7447 2/91

SN7492 3/91

SW938 2— P ( DTL > 5/91

BFQ 85 UHF HIGH GAIN AMPS 2/93

WINEGARD KU420 UHF ANT, 4BAY B0WTIE925
CONNECTOR FOR RIBBON CABLE 34 PIN.. 92

8243 16 LINE I/O EXTENDER CHIP 95

7805 ,7012,7905,7912 MIX/MATCH 4/93

AM/FM RADIO IC (UNTESTED) W/SPECS 10/93

POTS-LIN TAP/BBHG-10K, 100K, 1M 3/92

IC BOX (STORES 5< LABELS IC’S) 92

DIP SWITCHES-4, 6, 8 !!<10 POS 2/93

TV KNOBS 10/91

*****AMDEk COL OR 1 MON I TER. .. 9303*** * *
Val tage-Mate (swi tching regulator kit
with adjustable DC/DCvol tag* convgrs-
i on. Output vol tages: -24 to +3GVDC, 3
op. mode* < step-up, riown&in version -919
CHIP CAPS (SET OF 4,2EACH 2. 7!<3. 3pf ) 93

FPA104 INFRA-RED EMITTER/SENSOR 99

MINIATURE SPEAKER (1 1/2") 2/91

UK I DAT A , EPSON , CENTRON ICS PR I NTERS / TEL
CONVENIENCE PAPER PAKS.CONT. ROLL

TEAR AWAY RAZOR EDGE, IK SHEETS 916

LOWEST PRICES VERBATIM DISKETTES/CALL
TEK/TOOL ZERO INSERTION IC TEST SOCK-
ETS- 14 PIN-99 16 PIN-910

47p-f*< 470pf 1KV DISCS (NICE SIZE) 20/91

LM380 (IJLN22SO) 3/91

UDN7JSO GAS DISCHARGE DISF/DRVR. . 3/93

MICRO-CONTROLLER BOARD
(KJt/$99.50)

Term: MICRO-MART accepts Visa, MC and telephone COD’S. Minimum 'larder $10.00. Shipping —
U.S. orders, $2.00. Canada and other countries $3.50 (includes ins.). Shipping rate adjusted where
applicable. NJ residents add 5% sales tax

MICRO-MART • 508 CENTRAL AVE., WESTFIELD, NJ 07090 • (201)054-0008

130

CIRCLE 9 ON FREE INFORMATION CARD

CIRCLE 83 ON FREE INFORMATION CARD

SINE WAVE SUPER BOARD

* NO Internal Connection to T.V. 'Cr_) a***,. ./ ;Cj

O { > -K- t> ~jl~) ■{ ' .. . • .U=j

* Continuous Audio/ Video

Modulation TS^ m Cp ^ 0 0 $ W'\ Q

* AGC FOR STABILITY - ®%° 0 r$? o

* Quality Circuit Board Y* * O &£$$

* Silk Screened Parts Layout /CpGOo Y >

iiiiiiii

□ Aft Parts, and Wadd Qrofned Cabinet $1 29.00 *ship. & Hand. $5.95

AjiPdd^^^ 0 ^ Orahed Cabinet $149.00+ Ship. A Ha«d.$5.95

mmM

$M5£^

09-151-03

* eOMPtEf E REPAIR SERVICE -ON ML ITEMS . • • '

* AVAILABLE BY MAIL ORDER ONLY

* SEND Fell i fsl F O RAA AT1C3 ISI OrtSMER KITS ‘ : :: :' .

* HOBBY uSe ONLY/ NOT EOR UNAUTHORIZED RECEPTION OF T.V< SIGNALS

CERTIFIED' FU N D$ AN £ MON £V 08 0 EPS '
SHIPPED IMMEDIATELY.

PERSONAL CHECKS HELD f OR 3 WEEKS

fop ci^ANc;^;.:' : ' : ;

MASTgRCAPD/VISA/UPS/C.O.D.

4242 South 48th Street
Phoenix* Arizona 85040

NATIONAL

DELIVERY

ORDERS

ONLY:

INFO

PHONE:

131

CIRCLE 13 ON FREE INFORMATION CARD

JULY 1983

RADIO-ELECTRONICS

THE WORLD FAMOUS

CATALOG OF
ELECTRONICS

• AUDIO

• ELECTRONICS'®*

• and much.

1000's OF FASCINATINGNSflJ
FACTORY CLEAROUTS. \^1
SURPLUS SPECIALS AND ^
BARGAIN OFFERS NOT FOUNDS
IN STORES OR CATALOGS
ANYWHERE!

l^pmccM

ETCO ELECTRONICS
DEPT. 591

Mailing List Control Center
Box 840

Champlain, N.Y. 12919
I Enclose (cash OK);

Please rush postpaid

□ $1 for 1 year subscription to the
world famous ETCO catalog.

□ $3 Canadian & Foreign 1 year
subscription to the ETCO catalog.

□ 304 page handbook “BUILD YOUR

OWN EARTH STATION”. (TA025) $10.00

□ 360 pages MASTER HANDBOOK OF

TELEPHONES. (TA001) $11.00

| I I FREE - sample copy of the bargain
1 — 1 packed ETCO catalog. (USA only)

Name 1

_ Address

I City

| State

CIRCLE 50 ON FREE INFORMATION CARD

-Zip-

HIGH QUALITY 55 dB GAIN

MICROWAVE
TV SYSTEM

Variable from 1.9 to 2.5 GHz

The latest advance
in microwave
technology with a
SNOW-FREE
PICTURE.

Introductory

SPECIAL

*124

Includes
Tax and
Shipping

THIS UNIT COMES COMPLETE WITH:

• 20" Fiberglass Parabolic Dish

• Pre- Assembled Probe with
Down Converter

• Power Supply and Coax Switch

• 60' of RG-59/U Coax with Connector

• Transformer for 75 to 300 Ohms

• All Mounting Hardware for Fast
and Easy Installation

Send Cashiers Check or Money Order to:

(Personal Checks, allow 2-5 weeks to clear)

PROFESSIONAL VIDEO, Inc.

4670 Hollywood Blvd., Hollywood, Calif. 90027

219-0227

For C.O. D. Orders Call (213) 352 - 968 I

CIRCLE 43 ON FREE INFORMATION CARD

AlilAIinG

DEVICE}

PHASOR PAIN FIELD — Patented and recently developed
in our labs is being tested by Gov't for riot control. Soon to come
under weapons restrictions as an infernal machine. Easily hand-
held. Hazardous IF NOT USED WITH DISCRETION.

PPF-1 PLANS (sold for animal control) $15.00

INVISIBLE PAIN FIELD GENERATOR — Produces a di-
rectional field of moderately intense pain to back of head up to
50' . Cigarette pack size enclosure is easily hidden.

IPG-3 PLANS . . . $7.00 IPG-3K KIT & PLANS . . . $44.50

IPG-30 (assembled for animal control) $59.50

PHASOR STUN/BURNING WAND - Produces sufficient
electrical energy capable of burning flesh. Intended as a person-
al HpfpnQP Hpvirp

PSW-3 PLANS . . $8.00 PSW-3K KIT & PLANS . . $59.50

RUBY LASER RAY PISTOL — Intense visible red, burns,
hazardous, with parts sources.

RUBY PLANS (includes all part sources) $15.00

CARBON DIOXIDE LASER — Generates 20-40 watts of
continuous power capable of burning, cutting, hazardous, (with

all part sources) $15.00

LASER RIFLE — Produces 200-3000 pulses of 30 watt opti-
cal energy. Portable and easily hand-held.

LRG-3 PLANS $10.00

LRG-3K KIT PLANS (minus diode) $129.50

POCKET LASER — For the beginner, visible red “optical
version”, non-hazardous.

LHC-2 $5.00 LHC-2K KIT & PLANS $24.50

HIGH POWERED PORTABLE ENERGY SOURCE
FOR LASERS AND MAGNETIC WEAPONS - Explod-
ing wires, shockwave, etc. Miniature size.

HPS-1 PLANS. . ,$8.00 HPS-1K KIT & PLANS. . ,$49.50
PARTICLE BEAM WEAPON - PLANS $15.00

INFINITY XMTR — Uses telephone lines for selective home
or office listening while away on business or vacation.

INF-1 plans: $15.00

SEE IN DARK — Long range, total darkness.

SD-4 PLANS $10.00

LONG RANGE WIRELESS MIKE - Crystal clear quality
— miniature.

FBT-7 PLANS . . . $7.00 FBT-7K PLANS & KIT . . . $34.50
WIRELESS TELEPHONE TRANSMITTER - Long
range, automatic.

VWPM-5 PLANS $10.00 VWPM-5K PLANS & KIT $34.50

Send for FREE catalog descripton of above plus hundreds more
plans, kits and completed items. We accept MC or Visa or when
ordering, send check or money order. We pay shipping charges
■on orders over $50.00, otherwise include 10% with remittance.

SEND TO SCIENTIFIC SYSTEMS

DEPT. R8, BOX 716, AMHERST, N.H. 03031

OVER 70,000 ITEMS IN STOCK

DISCOUNT PRICES

ON ALL MAJOR INDUSTRIAL AND PERSONAL ELECTRONICS

132

TOTAL ELECTRONICS CENTER • LOWER PRICES • IMMEDIATE DELIVERY

WM. B. ALLEN SUPPLY COMPANY, INC.

OAA COE OCA 4 1601 basin street, new Orleans, la 70118 OAA BOB
_Oyy Louisiana toll free soo 462-9520 OUU

CIRCLE 26 ON FREE INFORMATION CARD

H commodore

NEW COMMODORE PRODUCTS

CBM 128-40 $ 695

CBM Cl 28-80 795

CBMB700 2990

CBM 1 520 Plotter 169

CBM 1701 Color Monitor 269

B Series Software Call

CBM 4023 Printer 399

SOFTWARE FOR CBM 64 £

Word Processing (WordPro 3 + ) $ 69

M File Database

(merge with Word Pro) 89

Quick Brown Fox 56

Writer / sAssistant(easyandflexible) ... 99

File Assistant(databasewith merge) ... 99

Spreadsheet Assistant 99

Pers. Finance Assist.(great reports) ... 45

Busicalc (Spreadsheet) 55

Coco II (buildyour own games easily). . . 45

Calc Result 125

General Ledger, A/R, A/P

(with check writing) ea.139

CBM EasyFinance 50

CBM EasyScript 80

CBM EasyFile 80

Data Manager 70

Stock( investment analysis) 80

Pet Emulator (emulates 4.0 basic) 30

Sprite- Master 29

Assembler Package (cassette or disk,
compiled, includes editor, loader,

disassembler) 39

Spacebelt 20

Retroball 34

ZWARK 25

INTERFACES & ACCESSORIES

80 Column Expander $159

VIC 1 600 Modem 95

VIC 1650 (auto answer, auto dial) 150

VIC 1525 Graphic Printer 329

VIC 1530 Datasette Recorder 65

VIC 1541 Disk Drive 329

VIC Svitch (connect 8 64's or Vies

to printer, dd) 149

PET-IEEE cable 33

IEEE- IEEE cable (2m) 43

Parallel Interface (Epson, Okidata,

IDS, NEC) 80

RS-232 Printer Interface (Okidata,

Diablo, etc.) 60

Programmers Reference Guide 18

Verbatim Diskettes (10 per box) 26

Victree (Programmers Utility) 75

VIC PRODUCTS & ACCESSORIES

8 K RAM Memory Expansion Cartridge ... $ 40

16K RAM 70

24K RAM 105

VIC 3 Slot Expander 27

VIC 6 Slot Expander 70

RS-232 Printer Interface 65

Cassette Interface 30

Gorf (64 also) 30

Omega Race 30

Arcade Joystick - Heavy duty w/2 firing
buttons! Great for the VIC or 64 25

MONITORS -GREAT
RESOLUTION (64 OR VIC)

Amdek Color I $ 299

Amdek II or III call

Panasonic CT1 60 279

Comrex 6500 - 13" Color 299

Transtar 20 (High Resolution

Green Phosphor) 129

Video/ Audio Cable 15

PRINTERS - LETTER QUALITY

CBM 8300, 40 cps

..$1450

Diablo 620, 25 cps

. 949

ComRiter, 1 7 cps

. . 819

Transtar 130, 16 cps (auto load.

wp features!)

769

NEC 7700 series

. . 2350

NEC 3500 series

. . 1600

PRINTERS - DOT MATRIX

CBM 8023, 150 cps/ graphics

. . 589

Epson FX Printer, 160 cps

. . 549

Epson MX-80FT

. . 459

Epson MX-80 w/Graftrax

. . 349

CBM Graphics for Epson

Okidata 82A, 1 20 cps (serial

and parallel)

. . 429

NEC 8023A (parallel)

. . 429

Okidata 92

. . 559

Star Gemini, 10

. . 329

Star Gemini, 15

. . 499

COMMODORE BUSINESS
SERIES

SuperPet (5 languages,

2 processors) $1409

CBM 8032 Computer, 80 Column . . . 1029

CBM Memory Expansion, 64K 359

CBM 8050, 1 mg. Dual Drive 1259

CBM 8250, 2 mg. Dual Drive 1395

CBM D9060, 5 mg. Hard Disk 1995

CBM D9090, 7.5 mg. Hard Disk 2295

CBM 2031 , 1 70K Single Drive (New) 489
DC Hayes Smart Modem 220

BUSINESS SOFTWARE

WordPro 4* or 5* $ 309

Administrator 489

VisiCalc (expanded) 199

The Manager (database) 199

BPI A/R, G/L, Job Cost, Inventory,

Payroll ea.325

MasterCard y Visa,
Money Order, Bank Check

COD (add $5) accepted.

Add 3% surcharge for credit cards.

In stock items shipped within 48 hours,

F.O.B, Dallas, Texas

All products shipped with manufacturer's
warranty.

Prices are subject to change without notice.

TO ORDER
CALL TOLL FREE
800-527-4893
800-442-1048

(Within Texas)

Business Hours
Mon.- Fri. 8 to 6, Sat. 10-2

Write for free catalog.

GAME OF THE MONTH

Adventu- Writer (make your
own adventure game) 39

PRODUCT OF THE MONTH

INTERPOD (intelligent IEEE
RS232, serial interface
for VIC or C64) $ 179

SJB DISTRIBUTORS INC.

10520 Plano Road, Suite 206
Dallas, Texas 75238

(214) 343-1328

CIRCLE 24 ON FREE INFORMATION CARD

133

JULY 1983

RADIO-ELECTRONICS JULY 1983

□ ART OF PRO-
GRAMMING THE 16K
ZX81. $6.25. Topics in-
clude full screen, scroll-
ing, PEEK & POKE,
plus actual working
programs.

□ THE 6809 COM-
PANION. $5.00. Writ-
ten for the average
assembly language
programmer. A discus-
sion of 6809 features &
reference work for the
6809 programmer.

□ PRACTICAL COM-
PUTER EX-
PERIMENTS. $4.50.

Fills in background to
microprocessor by con-
structing typical compu-
ter circuits using dis-
crete logic components.

□ ART OF PRO-
GRAMMING THE IK
ZX81. $5.00. How to
use the features of the
ZX81 in programs that
fit the 1 K machine and
are still fun to use.

□ INTRODUCTION
TO BASIC PRO-
GRAMMING TECH-
NIQUES. $5.00. Based
on author's own experi-
ence in learning BASIC
and helping others to
learn to program.

□ A MICROPROCES-
SOR PRIMER. $4.50.

Painless approach to
computing for the be-
ginner. Step-by-step
explains computer op-
erations and assembly.

□ POWER SUPPLY
PROJECTS. $4.50.

Contains designs and
construction details for
almost any power sup-
ply the experimenter is
likely to need.

□ REMOTE CON-
TROL PROJECTS.
$5.00. Radio-control
infra-red, visible light, &
ultrasonic systems are
all included, along with
methods of applying
them.

□ ELECTRONIC
TEST EQUIPMENT
CONSTRUCTION.
$4.50. Construction de-
tails of a wide range of
test equipment the ex-
perimenter can build at
home.

□ ELECTRONIC
PROJECTS USING
SOLAR CELLS. $5.00.

Simple circuits that
have numerous ap-
plications around the
home.

□ ELECTRONIC TIM-
ER PROJECTS. $5.00.

Timing circuits for
almost any application
the experimenter might
need. A most valuable
reference.

□ COUNTER DRIVER
& NUMERICAL-
DISPLAY PROJECTS.
$4.50. Features ap-
plications & projects
using various types of
numerical-display de-
vices.

□ PRACTICAL ELEC-
TRONICS CALCULA-
TIONS AND FORMU-
LAE. $7.50. A basic
reference work that
bridges the gap be-
tween complicated
technical theory & cut
and tried methods.

□ INTERNATIONAL
DIODE EQUIVALENTS
GUIDE. $5.75. Helps
you find substitutes for
the many different
types of semiconductor
diodes in use today.

□ INTERNATIONAL
TRANSISTOR EQUIV-
ALENTS GUIDE.

$7.50. Products of
more than 1 00 man-
ufacturers are listed &
cross-referenced with
possible replacements.

□ HOW TO MAKE
WALKIE TALKIES.

$5.00. Describes equip-
ment for low-power
handheld operation.

112 pages of must
reading for the dedi-
cated experimenter.

□ ELECTRONIC
CALCULATOR US-
ERS HANDBOOK.

$3.95. Presents formu-
lae data, methods of
calculation, conversion
factors & more from the
view of the calculator
user.

□ LINEAR 1C EQUIV-
ALENTS AND PIN
CONNECTIONS. $8.25.

Shows equivalents & pin
connections of a popular
user-oriented selection of
linear ICs.

□ ELECTRONIC
SYNTHESIZER PRO-
JECTS. $4.50.

□ 50 CIRCUITS US-
ING GERMANIUM,
SILICON & ZENER DI-
ODES. $3.75.

□ 50 PROJECTS US-
ING RELAYS, SCR’S
& TRIACS. $5.00.

□ 50 (FET) FIELD-
EFFECT TRANSIS-
TOR PROJECTS.
$4.50.

□ 50 SIMPLE LED
CIRCUITS. $4.25.

□ 50 CIRCUITS US-
ING 7400 SERIES
IC’S. $4.50.

□ 50 SIMPLE LED
CIRCUITS BOOK 2.
$3.95.

□ PROJECTS USING
555 IC S. $5.00.

□ PROJECTS USING
LM3900 IC’S. $4.75.

□ RADIO CONTROL
FOR BEGINNERS.
$4.50.

□ ELECTRONIC
GAMES $4.50.

□ SINGLE 1C PRO-
JECTS. $4.25.

□ RADIO CIRCUITS
USING IC’S. $4.50.

□ ELECTRONIC
PROJECTS FOR BE-
GINNERS. $5.00.

□ ELECTRONIC
MUSIC & CREATIVE
TAPE RECORDING.
$5.00.

□ ELECTRONIC
SECURITY DEVICES.
$5.00.

□ HOW TO BUILD
YOUR OWN SOLID-
STATE OSCILLO-
SCOPE. $5.00.

□ SECOND BOOK
OF CMOS 1C PRO-
JECTS. $4.25.

□ PRACTICAL CON-
STRUCTION OF PRE-
AMPS, TONE CON-
TROLS, FILTERS AND
ATTENUATORS.

$3.75.

□ BEGINNERS
GUIDE TO DIGITAL
TECHNIQUES. $3.75.

□ ELECTRONIC
HOUSEHOLD PRO-
JECTS. $4.50.

□ ELECTRONIC
MUSIC PROJECTS.
$4.50.

□ POPULAR ELEC-
TRONIC PROJECTS.
$3.75.

□ PROJECTS IN

OPTO-ELECTRONICS.

$5.00.

□ 30 SOLDERLESS
BREADBOARD PRO-
JECTS BOOK-1.

$5.75. Whenever possi-
ble the same parts are
used in several pro-
jects. Even a first-time
builder can complete
these circuits.

□ HOW TO GET
YOUR ELECTRONIC
PROJECTS WORK-
ING. $5.00. Helps you
troubleshoot and repair
home-built projects of
every description.

□ MINI-MATRIX
BOARD PROJECTS.
$5.00. A variety or pro-
jects that can all be
built upon a mini-matrix
board that has 10 strips
and is 24 holes long.

□ MODERN OP-AMP
PROJECTS. $5.00.

Wide range of special-
ized op-amp circuits in-
cluding lo-noise, lo-
distortion, ultra-hi input
impedance, etc.

□ MULTI-CIRCUIT
BOARD PROJECTS.
$5.00. 21 fairly simple
projects that can all be
built on a single
printed-circuit board. All
are powered by a 9V
battery.

□ 1C PROJECTS
FOR BEGINNERS.

$5.00. Inexpensive digi-
tal and linear IC's are
used to assemble this
selection of circuits in-
tended for the be-
ginner.

□ THE PRE-
COMPUTER BOOK.
$5.00. Aimed at the
absolute beginner with
no knowledge of com-
puters. A non-technical
discussion that helps
you enter the computer
world painlessly.

□ AN INTRODUC-
TION TO VIDEO.
$5.00. Perfect for the
person just about to
buy a VCR. Discusses
pros & cons of the var-
ious formats; video
discs; videotext, tape
copying and more.

□ PRACTICAL ELEC-
TRONIC BUILDING
BLOCKS— Book 1.
$5.00. All electronics
circuits consist of sim-
ple building blocks.
When you know how to
make the blocks you
can easily create your
own projects.

□ FIRST BOOK OF
TRANSISTOR EQUIV-
ALENTS. & SUB-
STITUTES. $3.75.

□ PRACTICAL COM-
PUTER EX-
PERIMENTS. $4.50.

□ ELECTRONICS
SIMPLIFIED CRYSTAL
SET CONSTRUCTION.
$4.50.

□ ELECTRONIC
HOUSEHOLD PRO-
JECTS. $4.50.

□ ANTENNA PRO-
JECTS. $5.00. Covers
practical antenna de-
signs including active,
loop & ferrite types that
are easy & inexpensive
to build.

□ RADIO STATIONS
GUIDE. $4.75. Com-
prehensive listing of
transmitters around the
world. Presents loca-
tion, frequency, power.

□ LONG DISTANCE
TV RECEPTION
(TVDX) FOR THE EN-
THUSIAST. $5.00.

Practical & au-
thoratative introduction
to this unusual aspect
of electronics.

□ CB PROJECTS.
$5.00. A number of
useful and interesting
designs for CB
accessories. Speech
processor, interference
filter & more.

□ CRYSTAL SET
CONSTRUCTION.
$4.50. Packed full of
easy to duplicate de-
signs for crystal radio
receivers.

□ AN INTRODUC-
TION TO RADIO DX-
ING. $5.00. Listen, in
your home, to broad-
casts originating
thousands of miles
away. Tells how you
can do it.

□ THE SIMPLE
ELECTRONIC CIR-
CUIT & COM-
PONENTS. $5.75. All

the fundamental theory
needed to lead to a full
understanding of the
simple electronic circuit
and its components.

□ ALTERNATING
CURRENT THEORY.

$5.75. Alternating cur-
rent theory without
which there can be no
comprehension of
speech, music, radio,
or Television.

□ MICROPROCESS-
ING SYSTEM & CIR-
CUITS. $7.50. A truly
comprehensive guide
to all of the elements of
a microprocessing
system.

□ COMMUNICATIONS.
$7.50. Covers most
modern communication
systems. Line, micro-
wave, submarine, sat-
ellite, digital multiplex,
radio & telegraphy.

□ FIRST BOOK OF
HI-FI SPEAKER EN-
CLOSURES. $4.50.

□ SOLID STATE
NOVELTY CIRCUITS.
$3.50.

□ 28 TESTED TRAN-
SISTOR PROJECTS.
$4.25.

□ SEMICONDUCTOR
TECHNOLOGY. $5.75.

Everything you always
needed to know about
solid-state devices in
one volume.

Electronics Paperback Books

Quality Paperbacks at Affordable Prices

ELECTRONIC TECHNOLOGY TODAY INC.

P.O. Box 83, Massapequa Park, NY 11762

Number of books ordered

Total Price of Books

Sales Tax (NY State Residents)

Shipping (75c 1st two books, 30c ea additional) .
TOTAL ENCLOSED

Name-

Address-

City. State

Prices good until August 30, 1983

134

AMATEUR
MICROWAVE
TV ANTENNA’S

1.9 to 2.5 GHz Frequency Range
50 db System Gain

Complete System (Rod Style as
pictured, 25 db Gain)

PS-3 assembled, tested $79.95

PS-3 kit form $64.95

Complete System (Dish Style as
pictured, 50 db Gain)

PS-5 assembled, tested $109.95

PS-5 kit form $79.95

All systems come
complete with
Accessory
package of

• Control Box

• 60 Coax Cable

• Mounting
Hardware

• Matching
Transformer

• Instructions

• 90 Day Warranty

S.E.I., Inc.

912 West Touhy Ave. • Park Ridge, IL 60068

To Order Call: 1-800-323-1327 Out of State
1-312-564-0104 In Illinois
For Information Call: 1-312-564-0104
C.O.D.’s Accepted • Special Quantity Pricing
Dealers Wanted

5% shipping and hand-
ling. 10% for out of Con-
tinental U.S.

CIRCLE 55 ON FREE INFORMATION CARD

OUR ISOLATORS
FOR YOUR
PROTECTION

Prevents:

disk drive woes,
printer interaction,
memory loss and damage due to lightning
or AC power line disturbances.

Commercial Grade Isolator

ISO-1 3 Isolated Sockets. . . $76.95

Industrial Grade Isolator

ISO-3 3 Double

Isolated Sockets. . . . 115.95

Laboratory Grade Isolator

ISO-17 4 Quad

Isolated Sockets. . . 200.95

Circuit Breaker

any model (Add-CB). . . Add 10.00
Remote Switch

any model (Add-RS). . . Add 18.00

Electronic Specialists, Inc.

171 S. Main St.. Box 389, Natick, MA01760

Toll Free Order Desk 1 *800-225-4876
MasterCard, VISA, American Express

CIRCLE 6 ON FREE INFORMATION CARD

ELECTRONIC KITS
FROM HAL-TRONIX

2304 MHZ DOWN CONVERTERS. TUNES IN ON
CHANNELS 2 TO 7 ON YOUR OWN HOME T.V. HAS
FREQUENCY RANGE FROM 2000 MHZ TO 2500
MHZ. EASY -TO CONSTRUCT AND COMES COM-
PLETE WITH ALL PARTS INCLUDING A DIE-CAST
ALUM CASE AND COAX FITTINGS, REQUIRE A
VARIABLE POWER SUPLY AND ANTENNA (Antenna
can be a dish type or coffee can type depending on the
signal strength in your area.)

2304 MOD 1 (Basic Kit) $19.95

(Less case & fittings)

2304 MOD 2 (Basic/Pre-amp) $29.95

(less case & fittings)

2304 MOD 3 (Hi-Gain Pre-amp) $39.95

(Includes case & fittings)

POWER SUPPLY FOR EITHER MODEL ABOVE IS
AVAILABLE. COMES COMPLETE WITH ALL PARTS,
CASE, TRANSFORMER, ANTENNA SWITCH AND
CONNECTORS (Kit) $24.95

Assembled $34.95

Slotted Microwave Antenna For Above
Downverters $39.95

PREAMPLIFIERS

HAL PA-19 — 1.5 mhz to 150 mhz. 19db gain operates
on 8 to 18 volts at lOma. Complete unit $8.95.

HAL PA-1.4 — 3 mhz to 1.4 ghz. 10 to 12 db.gain op-
erates on 8 to 1 8 volts at 1 0 ma. Complete unit $1 2.95.
(The above units are ideal for receivers, counters, etc.)

16 LINE TOUCH TONE DECODE KIT WITH P.C.

BOARD AND PARTS $69.95

12 LINE TOUCH TONE DECODER KIT WITH P.C.

BOARD AND PARTS $39.95

16 LINE ENCODER KIT, COMPLETE WITH CASE,

PAD AND COMPONENTS $39.95

12 LINE ENCODER KIT, COMPLETE WITH CASE,
PAD AND COMPONENTS $29.95

Complete Sets of P.C. Boards Available For: Unicorn
Robot Project and Heart-A-Matic Project.

MANY, MANY OTHER KITS AVAILABLE

Sand 20 cants stamp or S.A.S.E. tor Information and tlyar on other
HAL-TRONIX products. To ordar by phone: 1-313-285-1782.

Hal-Tronix

P.O. Box 1101

ORDERS OVER $25.00 WILL BE SHIPPED POSTPAID EXCEPT
ON ITEMS WHERE ADDITIONAL CHARGES ARE REQUESTED
ON ORDERS LESS THAN $25.00 PLEASE INCLUDE AOOITION
—R HANDLING AND MAILING CHARGES

SHIPPING

INFORMATION,

CIRCLE 75 ON FREE INFORMATION CARD

Order Line
800-435-0907
(outside Calif.)
Please use for
orders only

RANA Systems
Apple Drives

$395.00 w/controller
$295.00 w/o controller

SUPER 3.5am P P0WER SUPPLY
for APPLE — ► $82.00 Jj-

Diskette Storage BOX

5V 4 ia. 5 : 8in.. 5

*2.50ea X $1OP®if3.50^ $15.00

Bare Bones APPLE II
EUR O-

CONCORD

COMPUTER

PRODUCTS

2910 B E LA PALMA ££

ANAHEIM CA 92806

714 632 6790 CHtCK M0

10 MIN ' )WDI K I A WIS ADD b L . OR #K$ Dt . * 1
f feiqht PfRSOM .Him SS(»!

*10 49 -*?oo s?b0 - 499 - s 9°o send* - ! 00

bO -99 - 4»° bOO - 999 - II 00 for
100- ?40 - 8 00 1000- UP -Call catalog

MONITORS & &
ZENITH * ZVM-121

12in. 15MHz. /GREEN Pho».

I— $94.00 TV

BMC*BM-12EUN

12in20 MHz /GREEN Phos.
Non- Glare Screen

I— *134°°tV

BMC#BM1401RGB
13in «RGB» COLOR
with Apple interface!!

I— *425.00#

W/ 0 _ . . -48K RAM-

Key board

6QQQ

Diskette SALEH

“Wabash”

5k finch

1C.

(2vol.) Master
$49.95

w/o ujyy.

Pwr. Supply

SS/^D $17.50
SS/DD 27.40

DS/SD 0
DS/DD 32.40

$ 20.00
30.40 j
34.90

37.40

SOCKETS

W W p St

8 10 / 1.20
10/5.30 14 10/1.30

10/570 18 10/1.40

KV8.70 18 XV 180

XV9 70 20 XV2 70

Microswitch: Power Supply: APPLE

Keyboard :w/ Purchase : Reference Manl. 1

$ 75.00 | 1 79.00 • * 18.00

10/12 70 22 10/2.70

XV13.70 24 10/2.70

10/14.70 28 10/3.00

10/1770 40 10/3 90

wirewrap eotder

74LS

74LS00
74LS02
74LS03
74LS04
74LS05
74LS08
74LS09
74LS10
74LS1 1
74LS12
74LS13
74LS14
74LS15
74LS20
74LS21
74LS22
74LS26
74LS27
74LS28
74LS30
74LS32
74LS33
74LS37
74LS38
74LS42
74LS48
74LS49
74LS51
74LS54

74S00

74502

74503

74504

74505

74508

74509

74510

74511
74S1S
74S20
74S22
74S30

COMPONENTS

74LS55

74LS73

74LS74

74LS75

74LS76

74LS78

74LS83

74LS85

74LS86

74LS90

74LS91

74LS92

74LS93

74LS95

74LS96

74LS107

74LS109

74LS112

74LS113

74LS114

74LS122

74LS123

74LS125

74LS126

74LS132

74LS133

74LS136

74LS137

74LS138

74S32

74537

74538

74550

74551

74564

74565
74S74

74585

74586
74S112
74S124
74S132

.25 74LS139

.36 74LS145

.35 74LS147

.38 74LS148

38 74LS151

42 74LS153

48 74LS154

60 74LS155

.30 74LS156

.50 74LS157

85 74LS158

50 74LS160

50 74LS161

.65 74LS162

89 74LS163

38 74LS164

38 74LS165

38 74LS166

38 74LS168

38 74LS169

.45 74LS170

85 74LS173

45 74LS174

48 74LS175

58 74LS181

55 74LS190

.38 74LS191

.85 74LS192

50 74LS193

40 74S138

■85 74S140

85 74S151

25 74S157

.25 74S1 58

.35 74S161

35 74S163

.50 74S174

1.25 74S175

35 74S182

45 74S188

2.50 74S189

.50 74LS194

1.15 74LS195

175 74LS196

1.35 74LS197

.55 74LS221

.50 74LS240

1.75 74LS241

75 74LS242

.75 74LS243

.55 74LS244

.65 74LS245

69 74LS247

.85 74LS248

69 74LS249

.85 74LS251

.65 74LS253

.85 74LS257

1.75 74LS258

1.55 74LS259

1.55 74LS260

1.35 74LS266

65 74LS273

.55 74LS279

.85 74LS280

1.95 74LS283

89 74LS290

89 74LS293

.75 74LS295

.75 74LS298

85 74S1 94

40 74S1 95

95 74S201

95 74S240

95 74S24 1

175 74S244

3.75 74S251

95 74S253
95 74S257
1 75 74S258

1 55 74S260

4.95 74S275

.85 74LS299

.85 74LS323

75 74LS352

.75 74LS353

.95 74LS365

.95 74LS366

95 74LS367

.95 74LS368

1.25 74LS373

■85 74LS374

1.65 74LS375

1.10 74LS377

110 74LS378

1.10 74LS379

.55 74LS386

.55 74LS390

50 74LS393

.55 74LS395

1.25 74LS399

.55 74LS490

.55 74LS623

1.45 74LS668

45 74LS669

1.85 74LS670

.65 74LS683

.95 74LS685

85 74LS687

.95 74LS783

1.25 74S280

1.25 74S287

6.50 74S288

1.95 74S289

1.95 74S299

2.95 74S373

85 74S374

85 74S387

85 74S454

85 74S471

.55 74S472

12.95 74S474

6502 5.95 6800

6522 6.75 6802

6532 10.25 6809

6810 2.95 6845

6821 3.00 6847

6840 10.50 6850

LM300H

LM301N

LM301H

LM307H

LM308AN

LM309K

LM310

LM311

LM317K

LM318H

LM322

LM323K

LM324

LM339

LM348

LM358

LM380

LM381

LM386

LM531

LM555

LM556

LM558

LM565

LM566

LM703

LM709

LM710

LM711

LM720

LM723

LM733

LM741-8

LM741N-14

LM741H

LM747

LM775

12 50 6852 5.25 I

11.95 6860 9.50 |

3.25

41 16-150NS 8/13.95
4164-200NS 6.25

4164-150NS 7.25

CIRCLE 7 ON FREE INFORMATION CARD

-ELECTRONICS

SPARTAN

CTC9R

$139.95

X /ill Electronics Inc.

G* vV ^4/4

(516) 499-9500

6094 Jericho Tpke.
Commack, N.Y. 11725

Philips Remote
Cable Converter

Micro computer technology • Quartz controlled
1C s lock in picture & prevent drift • 60 channel
selections • Programmable time on & off • 24
hour LEO digital clock • Favorite channel mem-
ory & recall plus scan • Wireless hand held
infra-red transmitter system • Automatic fine
tune • Adaptable to any brand television • One
year warranty service.

CABLE TV ACCESSORIES

2 set coupler

3 set coupler

3 95

4 set coupler

4 50

F Connectors

Matching transformer

TV Game Switch

3 95

VHF-UHF AMP-28DB

29.95

2-WAY SWITCH for

a printers, modems,

A & \\ & computers

0 W 0 O 0 n (RS232)

w ( J $119.95

$35.95

DG115P

SGL WABER

Protect your
computer and

electronic equipment , c „ ....
from voltage spikes $45 g5

DG115S

^SCOTCH DISKETTES

5'/4 SSDD Soft Box 10 $29.95
5'/4 DSDD Soft Box 10 $39.95

REFURBISHED

MONITORS

9", 12", Commercial Grade

as low as $49.95

1500 Feet Cordless Phone $ 229.95

10 KM (6 miles) Cordless
Phone for Export Use Only

$325.00

BECKMAN
CIRCUITMATE 20

8 functions and 30 ranges -
Diode/transistor test function -
auto-polarity, auto-zero, and
auto-decimal - 10 Amps AC and
DC Current Capability - Transistor
Gain Test (hFE) - Conductance

$64.95

Jerrold 36 Channel
Remote CATV
Converter

w/on/off Fine Tuning $94.95
58 Channel Wireless $109.95

40 Chan nel VHF to UHF
~ Block Converter

IB 28.95 Ea.
24.95 4 & up

Deluxe Version - Features fine tuning knob,
matching X former & 2 cables $38.95

Dealers Welcome
Volume Visa. MC. BAC. Amex, 4% Add

nicrn.mtc C O D , money order, check

uiscounts Add {or Ship p jng

Min Order $25.00
International shipping Add’l
Prices subject to change
without notice
COD 2.00 Extra
‘ Add’l. shipping
for monitors

(516)
9500

to 7500
76 00 to 250.00

251.00 to 500 00

501.00 to 750 00

751.00 to 1000.00
Over 1000 00 .

Mon Th
9-8

Tu W F
9-6

ICLE 47 ON FREE INFORMATION CARD

ADVERTISING INDEX

RADIO-ELECTRONICS does not assume any responsibility for errors that may appear
in the index below.

Free Information Number Page

62 Abex 100

3 Active Electronic Sales Corp 115

— Advance Electronics 31

80 Advanced Computer Products 125

73 All Electronics Corp Ill

51 AMC Sales 102

56 AP Products 11

14 Appliance Service News 101

89 Arizona Electronic Surplus 119

60 BBC Metrawatt Cover II

41, 78 Beckman Instruments Cover III, 40

67 Beta Electronics 116

— Binary System 98

42 BK Precision Dynascan Corp 9

17 Bondhus Corp 28

— CD Electronics Inc 119

34 Chaney Electronics Inc 118

— CIE, Cleveland Institute of

Electronics Inc 34-37

44 Circuit Specialists Inc 115

2, 21 Communications Electronics 2,21

88 Components Express Inc 120

68 Computer Products

Peripherals Unltd 120

7 Concord Computer Products 135

48 Consolidated Electronics Inc 38

— Daetron 130

39 Digi-Key Corp 122,123

— Digitron Electronic 124

53 Direct Video Sales 39

99 Dokay Computer Products Inc 1 17

59 EICO 77

5 Electra Company 29

45 Electronic Rainbow 41

6 Electronic Specialists Inc 135

Electronic Technology

— Today Inc 79,134

33 Electronics Book Club 25

10 Etronix , 89

40 Firestick Antenna Company 91

— Fordham Radio 13, 15, 22

76 Formula International Inc 114

21 Gamma Electronics 120

84 Gilco International Inc 124

— Gladstone 92

31 Global Specialties Corp 23

— Grantham College of Engineering 92

— Graymark Inc 118

75 Hal-tronix 135

16 Heath Company 5

85 Hickok 79

— ICS Computer Training 91

94 Illinois Audio 91

20 Jameco Electronics 112,113

29 Javanco 124

49 JDR Microdevices Inc 126-129

97 Jensen Tools Inc 100

11 Jim-Pac Electronic Components . 26, 27

46 Kalglo Electronics Company Inc 79

83 KCS Electronics Corp 130

36 Keithly Instruments Inc 42

— McGraw-Hill Book Clubs 102-105

35 MCM 119

66 MFJ Enterprises Inc 110

12 Micro-Mart 130

— Monarchy Engineering Inc 118

77 Morrow 96, 97

— Netronics R D Ltd 39

90 Network Sales Inc 115

— New Horizons 75

— NRI Schools 16-19

— NTS Schools 84-87

61 OEM Distributing Company .... 100, 101

37, 100 Ora Electronics 32, 100, 101

58 Pacific 1 100

52 PAI A Electronics Inc 77

93 Paladin 28

9 Phillips-Tech Electronics 130

— Radio-Electronics Bookstore 81

86 Radio Shack 109

79 Ramsey Electronics Inc 121

27 R. F. Electronics 119

32 Sams Books 83

25 SCR Electronics Center 1 10

55 SEI 135

70, 71 Sencore 1

— Simple Simon Electronic Kits Inc 73

91 Simpson Electric Company 24

82 Sintec Company 30

24 SJB Distributors Inc 133

— Solder Absorbing Technology Inc.... 100

69 Solder Craft 118

23 Solid State Sales 110

28 Sony 20

57 Space Age Video Dist Inc 79

47 Spartan Electronics Inc 136

72 Symmetric Sound Systems 101

98 Sunnex Inc 100

38 Taft Electronics 94

8 Technical Electronics 136

74 Tektronix 7

30 Tinker Tron 91

43 Triton Mkt Corp 33

18 Ungar Cover IV

15 Video Engineering Supply Co 77

19 Wahl Clipper 81

13 Westech 131

95 Wersi 83

26 Wm B Allen Supply 132

TTEKEL

TECHNICAL ELECTRONICS,
YOUR SUPPLY SOURCE
WITH BARGAINS LIKE THESE:

RECHARGEABLE HI

AA CELL kJ 1

Standard AA nickel cadmium rechargeable battery.

Stock No. 16-2379 $.95 ea.

AUDIO AMP

Complete audio amp
includes volume/on-
off and tone controls.
Requires 6-9 VDC. Just the thing for PA systems,
record players, or intercoms!

Stock No. 36-3023 $4.95 ea.

4" SOLAR CELL

1 amp at .5 volts at
an unbelievably low price!

Stock No. 47-3029 $5.

ORDER TODAY! VISA, MASTERCARD & COD

accepted for phone orders. Please add $3.00
for UPS ground. Satisfaction guaranteed.

Call or write for your FREE CATALOG!

TECHNICAL ELECTRONICS

Dept. J P.0. Box 2361
Woburn, MA 01888 (617) 935-1717

CIRCLE 8 ON FREE INFORMATION CARD

FOR FREE
INFORMATION
USE THESE
POST-PAID
CARDS

Print your name,

address and Zip
Code on one of
the attached post-
age-paid cards.

Circle the number

(or numbers)
on the card that
corresponds to
the number at the
bottom of each
advertisement or
editorial item
that you want
information on.
Advertisers’ free-
information
numbers also
appear in the ad
index at the left
on the facing page.

Mail the card. It’s
Postage-Paid.

NOTE:

Use the postcard
address for Free
Product Infor-
mation only.
Address all
editorial inquiries
to Editor, RADIO-
ELECTRONICS,
200 Park Avenue
South, New York,
N.Y. 10003.

POSTAGE-PAID FREE INFORMATION CARD Only one card per person

REA783

101

111

121

131

141

151

102

112

122

132

142

152

103

113

123

133

143

153

104

114

124

134

144

154

105

115

125

135

145

155

106

116

126

136

146

156

107

117

127

137

147

157

108

118

128

138

148

158

• 79

109

119

129

139

149

159

100

110

120

130

140

150

160

2 □ Please send me 12 issues of RADIO-ELECTRONICS for $14.97 and bill me.
(Canada $17.97 — US Funds only)

NAME Please print

COMPANY NAME (if applicable)

ADDRESS

CITY STATE ZIP

IMPORTANT

VO I D after September 30, 1 983 Allow 6-8 weeks for delivery of first issue

POSTAGE-PAID FREE INFORMATION CARD Only one card per person

REA783

101

111

121

131

141

151

102

112

122

132

142

152

103

113

123

133

143

153

104

114

124

134

144

154

105

115

125

135

145

155

106

116

126

136

146

156

3 *7

107

117

127

137

147

157

108

118

128

138

148

158

109

119

129

139

149

159

100

110

120

130

140

150

160

2 □ Please send me 12 issues of RADIO-ELECTRONICS for $14.97 and bill me.
(Canada $17.97 — US Funds only)

NAME lease print

COMPANY NAME (if applicable)

ADDRESS

CITY STATE ZIP

IMPORTANT

VO I D after September 30, 1 983 Allow 6-8 weeks for delivery of first issue

NO POSTAGE
NECESSARY
IF MAILED
IN THE

UNITED STATES

BUSINESS REPLY CARD

FIRST CLASS PERMIT NO. 597 BOULDER, COLORADO

RadiaEleotnwtes

SUBSCRIPTION SERVICE
P.0. Box 2520

BOULDER, COLORADO 80321

NO POSTAGE
NECESSARY
IF MAILED
IN THE

UNITED STATES

BUSINESS REPLY CARD

FIRST CLASS PERMIT NO. 27346 PHILADELPHIA, PA.

POSTAGE WILL BE PAID BY ADDRESSEE

Radio-Electrralas.

FREE PRODUCT INFORMATION
P.0. Box 13775
PHILADELPHIA, PA. 19101

NO POSTAGE
NECESSARY
IF MAILED
IN THE

UNITED STATES

BUSINESS REPLY CARD

FIRST CLASS PERMIT NO. 27346 PHILADELPHIA. PA

POSTAGE WILL BE PAID BY ADDRESSEE

RadioElectroiiics.

FREE PRODUCT INFORMATION
P.0. BOX 13775
PHILADELPHIA PA. 19101

RADIO-ELECTRONICS 4SG39

Subscribe today to the magazine that keeps you up-to-date with the newest
ideas and innovations in electronics. (If you already are a subscriber, do a
friend a favor and pass this subscription card along to him.)

check offer preferred

□ 1 Year— 12 issues ONLY $14.97
(You save $3.03 over newsstand)

□ Canada — 12 issues $17.97

□ All other countries— 12 issues $22.47

□ Payment enclosed □ Bill Me

Name (Please Print)

Company Name (If applicable)

Address

City

Allow 6-8 weeks for delivery of first issue

□ 2 Years (SAVE MORE)— 24 issues $28.97
(You save $7.03 over newsstand)

□ Canada— 24 issues $34.97

□ All other countries— 24 issues $43.97

□ Check here if you are extending or
renewing your subscription

.State Zip

Offer valid in US $ Only.

For new
ideas in
i electronics
road
j Radio-
Electronics

Radio-Electronics
will carry up-to-the-
minute articles on:

• hobby computers

• solid-state technology

• TV games • Video

• color TV • stereo

• test equipment

• radio

• radar detectors

• industrial electronics

• servicing

TV-radio-stereo

• experimenter

circuits

• exceptional

construction

projects

Don’t take a
chance on missing
even one issue.
Subscribe now
and save!

NEW IDEAS AND
INNOVATIONS IN
ELECTRONICS

The newest ideas and
innovations in
electronics appear in
Radio-Electronics,
Keep up-to-date!

Subscribe Today!

Workaholics

Beckman DMMs
stay on the job when
others call it quits.

They’re a hard-nosed
breed of 3Vi digit hand-
held multimeters you can
always count on for out-
standing performance.

Staying power

Beckman DMMs
work up to 2000 hours
on a common 9V battery.

That’s ten times longer
than other DMMs. And
to prevent burnout on
the job, Beckman DMMs can withstand 1500 Vdc loads
and 6kV transients. Current ranges are protected with a
2A/250V fuse, and resistance ranges are protected up
to 500 Vdc.

Easy to work with

No matter how hard they work, they’re never hard to
work with. Their single rotary switch makes function and
range selection simple and sure. For your added conve-
nience, most Beckman DMMs have built-in 10- Amp capa-
bility and Insta-ohms® continuity indication. That means
you never have to carry an accessory shunt or wait for a
continuity check.

And to make sure
that the job is done
right the first time,
Beckman DMMs have
superior RF shield-
ing, and an impressive
22 Meg-ohm input
impedance that re-
duces circuit loading
to ensure accurate
readings.

No matter how
much the job de-
mands, you can count
on Beckman DMMs
to see you through.
There’s a Beckman DMM just right for every application.
Use the selection chart to find the model best for you.

For a closer look at the workaholics, see your
local Beckman distributor today. To locate the one nearest
you, call or write Beckman Instruments, Inc.,
Instrumentation Operations, 210 S. Ranger Street, Brea,
CA 92621. (714) 993-8803.

ECKMAN

SELECTION CHART

MODEL

SPECIAL FEATURES

BASIC

ACCU-

RACY

INSTA-

OHMS®

10 AMPS

SUG-

GESTED

RETAIL

PRICE

(U.S.)

Tech 300

Basic six functions

0.5%

$120

Tech 310

Added features

0.25%

145

Tech 310UL

UL-listed

0.25%

155

Tech 320B

Audible continuity beeper

0.1%

189

Tech 330

High accuracy & true RMS
(AC & DC)

0.1%

219

HD-100

Heavy duty (drop-proof,
contamination-proof)

0.25%

169

HD-110

Heavy duty, plus 10 Amps

0.25%

189

CIRCLE 41 ON FREE INFORMATION CARD

unGan

The Professionals’ Choice.

Form Plastics

Introducing Ungar’s New Light
Heat Gun For Heavyweigh

Comfortable
Pistol Grip,
Biomechanically,
Balanced

3 Position Pilot
Light Switch

Lightweight, (28
Ounce), Impact-
Resistant Body

Long-Life 975 F
Heating Element

Stainless Steel
Ventilated Heat
Shield

Cure Thermoset Adhesives Shrink Tubing

Heat Liquids

Peel Paint

At Ungar, we’ve designed the
ultimate heat gun for the hard-
working pro. Feature for feature,
no other heat gun can make your
job quicker, easier or safer.

To begin with, our new 6977 is
the lightest heat gun of its kind
(28 ounces). You can use it for
hours on end with maximum con-
trol and minimum fatigue. The
contoured handle provides a firm
grip and remains cool at all times.

The 6977 is a high-temp, high
air volume heat gun with power

CIRCLE 18 ON FREE INFORMATION CARD

unGaR*

Division of Eldon Industries, Inc.
Compton, California 90220

for the heaviest jobs. It delivers
975°F to the nozzle in seconds
and is perfect for curing adhe-
sives, forming plastics, shrinking
tubing, peeling paint and just
about any other tough job you’ll
ever run across.

And the 6977 can take it in the
real world. The body is made of
rugged, impact-resistant Valox®
855. It features a proven, reliable
high-rpm motor, low noise opera-
tion, long-life heating element and
a 6-foot, 3-conductor ground cord.

A wide range of optional
attachments can provide addi-
tional versatility. The new Ungar
6977 heat gun . . . light years
ahead of the competition, is
Underwriter’s Laboratory, Inc.
listed. For more information,
contact your local Ungar distribu-
tor or call Ungar in California
1-213-774-5950.

Internet Archive Audio

Featured

Top

Images

Featured

Top

Software

Featured

Top

Books

Featured

Top

Video

Featured

Top

Mobile Apps

Browser Extensions

Archive-It Subscription

Save Page Now

Full text of "Radio Electronics (42 issues)"

See other formats